This presentation provides an overview of structural bolting and welding used in steel construction. It discusses the different types of bolted connections including bearing and slip-critical joints. The presentation covers bolt types, installation methods like snug-tight and turn-of-nut, and inspection requirements. It also provides information on welding processes and considerations for field welding. The goal is to help construction managers understand the technical details and their impacts on schedule, cost, and project management.
This presentation provides information on bolting and welding structural steel connections. It discusses the benefits of structural steel construction and the unique aspects of steel erection. The presentation covers the types of bolts used in structural steel, including ASTM specifications and sizes. It describes bolted joint types such as bearing and slip-critical joints. The presentation also explains bolting procedures and considerations for bolted connections in structural steel framing.
Fillet welds are commonly used to join corners, Ts, and lap joints in heavy machinery, ships, and buildings because they are more economical than groove welds. The strength of a fillet weld depends on the product of its theoretical throat thickness and effective weld length. Fillet weld sizes determine the theoretical throat, with the size and a 45 degree angle used to calculate it. Standards specify minimum fillet weld sizes based on base metal thickness to support loads without being excessive to minimize distortion and costs. Quality control inspects leg size, throat, convexity, and concavity using welding gages.
Twi cswip welding inspection notes and questionsThang Do Minh
The document discusses the duties of a welding inspector, including visual inspection of welds to identify defects and ensure they meet acceptance criteria. It describes tools that can aid inspection like magnification lenses. It outlines a code of practice for an inspection department, including checking documents, materials, equipment and welder qualifications before welding, monitoring the welding process and variables during welding, and inspecting the final weld for defects, dimensions and heat treatment after welding. Repairs should follow an authorized procedure and be re-inspected upon completion.
This document provides an overview of structural steel connections using bolting and welding. It discusses the benefits of structural steel construction and the unique aspects of steel erection. The two primary connection methods, bolting and welding, are explained. Structural bolting is covered in detail, including bolt types, sizes, parts of the assembly, and different bolted joint types such as bearing and slip-critical joints. Considerations for structural welding are also presented. The document aims to provide technical background knowledge for bolting and welding in structural steel construction.
This document discusses the selection process for different types of welding electrodes. It describes consumable electrodes that are classified based on their flux coatings to suit different arc characteristics, welding positions, and quality requirements. The key types of flux coatings include cellulosic, rutile, iron oxide, and basic low-hydrogen coatings. Important constituents in flux coatings like TiO2, CaCO3, and CaF2 are outlined. Guidelines for selecting electrode size based on current and coating factor are also provided. Classification systems for coated electrodes and guidelines for selecting between pure, thoriated, and zirconiated tungsten electrodes are summarized.
Welded connections can join metal pieces through a metallurgical bond. Common welded joints include butt joints, fillet welds, slot welds, and plug welds. Fillet welds join surfaces at right angles and have a triangular cross-section. Specifications cover weld sizes, lengths, and stresses. Advantages of welding include increased strength and reduced weight, while disadvantages include potential cracking and distortion during cooling. Design of welded joints involves calculating weld sizes and lengths to transmit required loads based on permissible stresses.
Peaking and banding refer to the roundness and straightness of shell plates around vertical and horizontal joints in storage tanks. Peaking is measured using a horizontal sweep board along vertical joints, while banding is measured using a vertical sweep board along horizontal joints. Acceptance criteria per API standards allow for peaking deviations of up to 13 mm and banding deviations of up to 13 or 25 mm depending on the standard. Proper measurement procedures involve visually inspecting the tank, positioning the sweep board accurately, and taking measurements at a minimum of 8 locations around the tank circumference.
This presentation provides information on bolting and welding structural steel connections. It discusses the benefits of structural steel construction and the unique aspects of steel erection. The presentation covers the types of bolts used in structural steel, including ASTM specifications and sizes. It describes bolted joint types such as bearing and slip-critical joints. The presentation also explains bolting procedures and considerations for bolted connections in structural steel framing.
Fillet welds are commonly used to join corners, Ts, and lap joints in heavy machinery, ships, and buildings because they are more economical than groove welds. The strength of a fillet weld depends on the product of its theoretical throat thickness and effective weld length. Fillet weld sizes determine the theoretical throat, with the size and a 45 degree angle used to calculate it. Standards specify minimum fillet weld sizes based on base metal thickness to support loads without being excessive to minimize distortion and costs. Quality control inspects leg size, throat, convexity, and concavity using welding gages.
Twi cswip welding inspection notes and questionsThang Do Minh
The document discusses the duties of a welding inspector, including visual inspection of welds to identify defects and ensure they meet acceptance criteria. It describes tools that can aid inspection like magnification lenses. It outlines a code of practice for an inspection department, including checking documents, materials, equipment and welder qualifications before welding, monitoring the welding process and variables during welding, and inspecting the final weld for defects, dimensions and heat treatment after welding. Repairs should follow an authorized procedure and be re-inspected upon completion.
This document provides an overview of structural steel connections using bolting and welding. It discusses the benefits of structural steel construction and the unique aspects of steel erection. The two primary connection methods, bolting and welding, are explained. Structural bolting is covered in detail, including bolt types, sizes, parts of the assembly, and different bolted joint types such as bearing and slip-critical joints. Considerations for structural welding are also presented. The document aims to provide technical background knowledge for bolting and welding in structural steel construction.
This document discusses the selection process for different types of welding electrodes. It describes consumable electrodes that are classified based on their flux coatings to suit different arc characteristics, welding positions, and quality requirements. The key types of flux coatings include cellulosic, rutile, iron oxide, and basic low-hydrogen coatings. Important constituents in flux coatings like TiO2, CaCO3, and CaF2 are outlined. Guidelines for selecting electrode size based on current and coating factor are also provided. Classification systems for coated electrodes and guidelines for selecting between pure, thoriated, and zirconiated tungsten electrodes are summarized.
Welded connections can join metal pieces through a metallurgical bond. Common welded joints include butt joints, fillet welds, slot welds, and plug welds. Fillet welds join surfaces at right angles and have a triangular cross-section. Specifications cover weld sizes, lengths, and stresses. Advantages of welding include increased strength and reduced weight, while disadvantages include potential cracking and distortion during cooling. Design of welded joints involves calculating weld sizes and lengths to transmit required loads based on permissible stresses.
Peaking and banding refer to the roundness and straightness of shell plates around vertical and horizontal joints in storage tanks. Peaking is measured using a horizontal sweep board along vertical joints, while banding is measured using a vertical sweep board along horizontal joints. Acceptance criteria per API standards allow for peaking deviations of up to 13 mm and banding deviations of up to 13 or 25 mm depending on the standard. Proper measurement procedures involve visually inspecting the tank, positioning the sweep board accurately, and taking measurements at a minimum of 8 locations around the tank circumference.
Welding causes distortion due to differential heating and cooling rates during the process. When heat is applied to part of a structure, it expands locally. If the structure is restrained from expanding uniformly, compressive and tensile stresses develop which can result in distortion. Three factors influence distortion: 1) temperature gradients between regions of the structure, 2) restraint from thermal expansion, and 3) yield strength and modulus of the material at welding temperatures. Distortion can be controlled by techniques such as pre-setting parts, clamping during welding, and post-weld heat treatment.
The document discusses various welding defects that can be visually detected, including cracks, lack of solid metal, lack of fusion, lack of smoothly blended surfaces, and miscellaneous defects. It provides details on different types of each defect, their causes, and methods for prevention. It also discusses welding repairs, noting that repairs require authorization and testing to ensure defects have been fully removed before performing the repair weld.
The document discusses residual stresses and distortion that occur during welding. It explains that residual stresses develop due to local expansion and contraction during welding, and are locked in as elastic strain. Distortion results from the movement caused by these welding stresses. The document outlines various factors that influence residual stress and distortion, such as heat input, restraint, and weld metal volume. It also discusses different types of distortion and several techniques for controlling distortion, such as joint design, offsetting, balanced welding, and clamping.
This presentation provides technical background on bolting and welding structural steel connections. It discusses the benefits of structural steel construction and unique aspects of steel erection. The presentation covers common bolt types and sizes, bolted joint types including bearing and slip critical, installation methods like snug-tightening and pretensioning, and weld types and inspection methods. The objective is to provide construction managers and contractors knowledge on properly connecting structural steel.
1) Two-way slabs are slabs with reinforcement in two directions because bending occurs in both directions when the L/S ratio is less than 2.
2) The document discusses various types of two-way slabs and design methods, focusing on the direct design method (DDM).
3) DDM involves determining the total factored static moment, distributing it to positive and negative moments, then distributing those moments to column and middle strips based on ratios of flexural and torsional stiffness.
This document discusses corrosion of steel reinforcement in concrete. It outlines the mechanisms of corrosion, including how steel becomes passive in high pH concrete but can become depassivated by chlorides or carbonation. Chlorides from deicing salts, seawater, or contaminated aggregates are common sources of corrosion. Corrosion causes cracking and deterioration of concrete structures like bridges and marine structures. Control methods focus on using low permeability concrete mixes with good cover to prevent ingress of chlorides and carbonation.
The document discusses welding symbols and weld joint design according to ISO standards. It covers elementary weld symbols, supplementary symbols, dimensioning of welds, examples of weld joint applications, edge preparation, basic joint types including butt, tee, lap and corner joints, applicable welds for each joint type, and welding positions.
This document is the Indian Standard specification for galvanized steel sheets, both plain and corrugated. It outlines the requirements, classifications, testing procedures and tolerances for galvanized steel sheets intended for general purposes like panelling and roofing. The standard specifies three classifications for galvanized plain and corrugated sheets based on the grade of raw material used. It also provides requirements for the zinc coating thickness, bend testing, coating mass determination and retests in case of failure. Dimensions and tolerances for plain sheets/coils are defined.
This document discusses the selection of filler wires. It begins with an objective to learn about filler wires, ASME Section IX Table QW-422 for material grades and chemical compositions, and SFA numbers. It then introduces the differences between filler wires and electrodes, and the nomenclature used for filler wires. Examples are provided for selecting the correct filler wire based on the base metal, welding process, and referring to ASME standards. The conclusion emphasizes that filler wire selection depends on the welding process, base metal, joint type, and referencing ASME codes.
Describe type of welding joint design and welding symbols that usually used in welding design
After completing this chapter, the student should be able to
understand the basics of joint design.
list the five major types of joints.
list seven types of weld grooves.
identify the major parts of a welding symbol.
explain the parts of a groove preparation.
describe how nondestructive test symbols are used.
Each joint’s design affects the quality and cost of the completed weld.
Selecting the most appropriate joint design for a welding job requires special attention and skill.
Welding symbols are the language used to let the welder know exactly what welding is needed.
The welding symbol is used as shorthand and can provide the welder with all of the required information to make the correct weld.
Cswip welding inspection notes and questionsKarthik Banari
The document discusses the duties of a welding inspector, including visual inspection of welds to identify defects and ensure they meet acceptance criteria. It describes tools that can aid inspection like magnification lenses. It outlines a code of practice for an inspection department, including checking documents, materials, equipment and welder qualifications before welding, monitoring the welding process and variables during welding, and inspecting the final weld for defects, dimensions and heat treatment after welding. Repairs should follow an authorized procedure and be re-inspected upon completion.
09-Strength of Gusset Plate (Steel Structural Design & Prof. Shehab Mourad)Hossam Shafiq II
1. The document discusses the methods to calculate the tensile strength of a gusset plate connection, including yielding on the gross area, fracture at the net area, and block shear failure.
2. It provides an example calculation for a gusset plate with given dimensions and materials. The tensile strength is calculated as 445.5 kN for yielding, 504.9 kN for fracture, and 490.68 kN for block shear.
3. A summary is given showing the strengths calculated for the bolted connection using different limit states like slip resistance and bearing failure are also included for reference. The governing strength is reported as 393.9 kN based on fracture of the effective area.
This document discusses the design of compression members in steel structures. It begins by defining compression members as members subjected to compressive stresses, such as columns, struts, and compression flanges. It notes that compression members are more prone to buckling than tension members. The document then discusses factors that influence the buckling strength of compression members, such as the member's length, cross-sectional properties, end conditions, and bracing. It also discusses eccentric loading of columns and the various sections that can be used or built up for compression members.
The document discusses various types of discontinuities and defects that can occur in welding, including cracks, porosity, inclusions, insufficient penetration, and more. It defines discontinuities as interruptions in material structure that are not necessarily defects, while defects render a part unable to meet standards. Causes, preventions, and potential repairs are provided for each issue. Engineering problems can arise from design mistakes, while weld process issues relate to techniques and metallurgy.
This document provides a classification and overview of common welding defects. It divides defects into three main categories: planar defects, linear volumetric defects, and non-planar defects. Examples of each type of defect are given. The document also describes specific defect types such as cracks, inclusions, lack of fusion, porosity, overlap, undercut and provides potential causes of each.
Steel is widely used for bridge construction due to its strength, ductility, and cost-effectiveness. Various types of steel are used including carbon steel, high-strength steel, weathering steel, and stainless steel. Welding is the primary method for joining steel components in bridges. Common welding processes for bridges include shielded metal arc welding, submerged arc welding, and gas metal arc welding. Proper selection of welding processes and steel types is important for achieving the required strength and durability of steel bridges.
WELD DEFECTS FOR VISUAL INSPECTION.pptxwaftech2017
This document discusses various welding defects and how to prevent them. It identifies the most common defects such as cracks, underfill, porosity, undercut, overlap, incomplete fusion, spatter, excessive penetration, incomplete root penetration, concave/convex fillet welds, offset, slag inclusions, and arc strikes. For each defect, it provides a definition and recommendations on how to avoid the defect through proper joint preparation, parameter adjustment, technique, cleaning, and equipment maintenance. The overall objective is to avoid defects through correct design, tools, procedures and operator training in order to improve productivity and reduce costs.
The document discusses weld defect acceptance criteria according to different codes such as ASTM B31.1, ASME VIII, ASME B31.3, and AWS D1.1. It provides details on acceptance limits for various weld defects depending on the examination method, material thickness, loading conditions, and material application. Defects discussed include cracks, lack of fusion, incomplete penetration, undercuts, porosity, and reinforcement. Acceptance criteria include maximum defect sizes, numbers of defects allowed, cumulative lengths of defects, and distances between defects.
The document discusses various welding defects including lamellar tearing, porosity, underfill, insufficient
penetration, wagon tracks, arc strikes, and incomplete fusion. Lamellar tearing occurs beneath welds in rolled steel
plate and is caused by transverse strain from welding, a weld orientation parallel to inclusions, and poor material
ductility. Porosity is caused by absorbed gases like nitrogen, oxygen, and hydrogen which become trapped during
solidification. Prevention methods for defects include using proper joint design, welding techniques, materials, and
preheating when necessary. Defects require removal and rewelding to repair.
Welding is a very commonly used permanent joining process.
A welding joint is a point or edge where two or more pieces of metal or plastic are joined together. They are formed by welding two or more workpieces (metal or plastic) according to a particular geometry. Five types of joints referred to by the American Welding Society: butt, corner, edge, lap, and tee. These configurations may have various configurations at the joint where actual welding can occur.
This presentation provides technical background on bolting and welding structural steel connections. It discusses the benefits of structural steel construction and unique aspects of steel erection. The presentation covers common bolt types and sizes, bolted joint types including bearing and slip critical, installation methods like snug-tightening and pretensioning, and weld types and inspection methods. The objective is to provide construction managers and contractors knowledge on properly connecting structural steel.
The document discusses bolted connections in steel structures. It covers various types of bolts used in structural connections, including unfinished bolts, high-strength bolts, and anchor rods. It describes methods for pre-tensioning high-strength bolts, requirements for bolt hole sizes and spacing, and factors that influence the failure of bolted joints. The document also summarizes design considerations and examples for bolted joints subjected to axial forces, eccentric shear forces, shear and tension forces, and tension loads.
Welding causes distortion due to differential heating and cooling rates during the process. When heat is applied to part of a structure, it expands locally. If the structure is restrained from expanding uniformly, compressive and tensile stresses develop which can result in distortion. Three factors influence distortion: 1) temperature gradients between regions of the structure, 2) restraint from thermal expansion, and 3) yield strength and modulus of the material at welding temperatures. Distortion can be controlled by techniques such as pre-setting parts, clamping during welding, and post-weld heat treatment.
The document discusses various welding defects that can be visually detected, including cracks, lack of solid metal, lack of fusion, lack of smoothly blended surfaces, and miscellaneous defects. It provides details on different types of each defect, their causes, and methods for prevention. It also discusses welding repairs, noting that repairs require authorization and testing to ensure defects have been fully removed before performing the repair weld.
The document discusses residual stresses and distortion that occur during welding. It explains that residual stresses develop due to local expansion and contraction during welding, and are locked in as elastic strain. Distortion results from the movement caused by these welding stresses. The document outlines various factors that influence residual stress and distortion, such as heat input, restraint, and weld metal volume. It also discusses different types of distortion and several techniques for controlling distortion, such as joint design, offsetting, balanced welding, and clamping.
This presentation provides technical background on bolting and welding structural steel connections. It discusses the benefits of structural steel construction and unique aspects of steel erection. The presentation covers common bolt types and sizes, bolted joint types including bearing and slip critical, installation methods like snug-tightening and pretensioning, and weld types and inspection methods. The objective is to provide construction managers and contractors knowledge on properly connecting structural steel.
1) Two-way slabs are slabs with reinforcement in two directions because bending occurs in both directions when the L/S ratio is less than 2.
2) The document discusses various types of two-way slabs and design methods, focusing on the direct design method (DDM).
3) DDM involves determining the total factored static moment, distributing it to positive and negative moments, then distributing those moments to column and middle strips based on ratios of flexural and torsional stiffness.
This document discusses corrosion of steel reinforcement in concrete. It outlines the mechanisms of corrosion, including how steel becomes passive in high pH concrete but can become depassivated by chlorides or carbonation. Chlorides from deicing salts, seawater, or contaminated aggregates are common sources of corrosion. Corrosion causes cracking and deterioration of concrete structures like bridges and marine structures. Control methods focus on using low permeability concrete mixes with good cover to prevent ingress of chlorides and carbonation.
The document discusses welding symbols and weld joint design according to ISO standards. It covers elementary weld symbols, supplementary symbols, dimensioning of welds, examples of weld joint applications, edge preparation, basic joint types including butt, tee, lap and corner joints, applicable welds for each joint type, and welding positions.
This document is the Indian Standard specification for galvanized steel sheets, both plain and corrugated. It outlines the requirements, classifications, testing procedures and tolerances for galvanized steel sheets intended for general purposes like panelling and roofing. The standard specifies three classifications for galvanized plain and corrugated sheets based on the grade of raw material used. It also provides requirements for the zinc coating thickness, bend testing, coating mass determination and retests in case of failure. Dimensions and tolerances for plain sheets/coils are defined.
This document discusses the selection of filler wires. It begins with an objective to learn about filler wires, ASME Section IX Table QW-422 for material grades and chemical compositions, and SFA numbers. It then introduces the differences between filler wires and electrodes, and the nomenclature used for filler wires. Examples are provided for selecting the correct filler wire based on the base metal, welding process, and referring to ASME standards. The conclusion emphasizes that filler wire selection depends on the welding process, base metal, joint type, and referencing ASME codes.
Describe type of welding joint design and welding symbols that usually used in welding design
After completing this chapter, the student should be able to
understand the basics of joint design.
list the five major types of joints.
list seven types of weld grooves.
identify the major parts of a welding symbol.
explain the parts of a groove preparation.
describe how nondestructive test symbols are used.
Each joint’s design affects the quality and cost of the completed weld.
Selecting the most appropriate joint design for a welding job requires special attention and skill.
Welding symbols are the language used to let the welder know exactly what welding is needed.
The welding symbol is used as shorthand and can provide the welder with all of the required information to make the correct weld.
Cswip welding inspection notes and questionsKarthik Banari
The document discusses the duties of a welding inspector, including visual inspection of welds to identify defects and ensure they meet acceptance criteria. It describes tools that can aid inspection like magnification lenses. It outlines a code of practice for an inspection department, including checking documents, materials, equipment and welder qualifications before welding, monitoring the welding process and variables during welding, and inspecting the final weld for defects, dimensions and heat treatment after welding. Repairs should follow an authorized procedure and be re-inspected upon completion.
09-Strength of Gusset Plate (Steel Structural Design & Prof. Shehab Mourad)Hossam Shafiq II
1. The document discusses the methods to calculate the tensile strength of a gusset plate connection, including yielding on the gross area, fracture at the net area, and block shear failure.
2. It provides an example calculation for a gusset plate with given dimensions and materials. The tensile strength is calculated as 445.5 kN for yielding, 504.9 kN for fracture, and 490.68 kN for block shear.
3. A summary is given showing the strengths calculated for the bolted connection using different limit states like slip resistance and bearing failure are also included for reference. The governing strength is reported as 393.9 kN based on fracture of the effective area.
This document discusses the design of compression members in steel structures. It begins by defining compression members as members subjected to compressive stresses, such as columns, struts, and compression flanges. It notes that compression members are more prone to buckling than tension members. The document then discusses factors that influence the buckling strength of compression members, such as the member's length, cross-sectional properties, end conditions, and bracing. It also discusses eccentric loading of columns and the various sections that can be used or built up for compression members.
The document discusses various types of discontinuities and defects that can occur in welding, including cracks, porosity, inclusions, insufficient penetration, and more. It defines discontinuities as interruptions in material structure that are not necessarily defects, while defects render a part unable to meet standards. Causes, preventions, and potential repairs are provided for each issue. Engineering problems can arise from design mistakes, while weld process issues relate to techniques and metallurgy.
This document provides a classification and overview of common welding defects. It divides defects into three main categories: planar defects, linear volumetric defects, and non-planar defects. Examples of each type of defect are given. The document also describes specific defect types such as cracks, inclusions, lack of fusion, porosity, overlap, undercut and provides potential causes of each.
Steel is widely used for bridge construction due to its strength, ductility, and cost-effectiveness. Various types of steel are used including carbon steel, high-strength steel, weathering steel, and stainless steel. Welding is the primary method for joining steel components in bridges. Common welding processes for bridges include shielded metal arc welding, submerged arc welding, and gas metal arc welding. Proper selection of welding processes and steel types is important for achieving the required strength and durability of steel bridges.
WELD DEFECTS FOR VISUAL INSPECTION.pptxwaftech2017
This document discusses various welding defects and how to prevent them. It identifies the most common defects such as cracks, underfill, porosity, undercut, overlap, incomplete fusion, spatter, excessive penetration, incomplete root penetration, concave/convex fillet welds, offset, slag inclusions, and arc strikes. For each defect, it provides a definition and recommendations on how to avoid the defect through proper joint preparation, parameter adjustment, technique, cleaning, and equipment maintenance. The overall objective is to avoid defects through correct design, tools, procedures and operator training in order to improve productivity and reduce costs.
The document discusses weld defect acceptance criteria according to different codes such as ASTM B31.1, ASME VIII, ASME B31.3, and AWS D1.1. It provides details on acceptance limits for various weld defects depending on the examination method, material thickness, loading conditions, and material application. Defects discussed include cracks, lack of fusion, incomplete penetration, undercuts, porosity, and reinforcement. Acceptance criteria include maximum defect sizes, numbers of defects allowed, cumulative lengths of defects, and distances between defects.
The document discusses various welding defects including lamellar tearing, porosity, underfill, insufficient
penetration, wagon tracks, arc strikes, and incomplete fusion. Lamellar tearing occurs beneath welds in rolled steel
plate and is caused by transverse strain from welding, a weld orientation parallel to inclusions, and poor material
ductility. Porosity is caused by absorbed gases like nitrogen, oxygen, and hydrogen which become trapped during
solidification. Prevention methods for defects include using proper joint design, welding techniques, materials, and
preheating when necessary. Defects require removal and rewelding to repair.
Welding is a very commonly used permanent joining process.
A welding joint is a point or edge where two or more pieces of metal or plastic are joined together. They are formed by welding two or more workpieces (metal or plastic) according to a particular geometry. Five types of joints referred to by the American Welding Society: butt, corner, edge, lap, and tee. These configurations may have various configurations at the joint where actual welding can occur.
This presentation provides technical background on bolting and welding structural steel connections. It discusses the benefits of structural steel construction and unique aspects of steel erection. The presentation covers common bolt types and sizes, bolted joint types including bearing and slip critical, installation methods like snug-tightening and pretensioning, and weld types and inspection methods. The objective is to provide construction managers and contractors knowledge on properly connecting structural steel.
The document discusses bolted connections in steel structures. It covers various types of bolts used in structural connections, including unfinished bolts, high-strength bolts, and anchor rods. It describes methods for pre-tensioning high-strength bolts, requirements for bolt hole sizes and spacing, and factors that influence the failure of bolted joints. The document also summarizes design considerations and examples for bolted joints subjected to axial forces, eccentric shear forces, shear and tension forces, and tension loads.
This document discusses composite construction and cambering of steel beams. It provides information on:
1) The composite construction process including use of composite metal decking, shear connectors, and concrete pouring to create a composite floor system that is stronger and stiffer than steel alone.
2) The advantages of composite construction such as reduced steel needs, lighter weight, and increased spans.
3) The cambering process of inducing a slight curvature in steel beams to compensate for deflection under loads in order to achieve a level floor slab.
4) When cambering is appropriate such as for filler beams, and when it is not such as for moment connected beams. Alternative methods to cambering like
Design of steel structure as per is 800(2007)ahsanrabbani
It does not offer resistance against rotation and also termed as a hinged or pinned connections.
It transfers only axial or shear forces and it is not designed for moment
It is generally connected by single bolt/rivet and therefore full rotation is allowed
This document provides an overview of connections and bracing configurations in structural steel construction. It defines simple connections, which are designed to be flexible, and moment connections, which are designed to be rigid or semi-rigid. Common types of simple and moment connections are described. The document also discusses braced frames, rigid frames, and combination frames that are used for lateral stability. Specific bracing configurations like X, chevron, and eccentric bracing are explained.
1. The document summarizes the design of a steel intensive toilet block in India under the Swachh Bharat initiative.
2. It includes the design of steel connections and members using STAAD and the types of connections that were designed, which include shear and moment connections.
3. Key structural elements like columns, beams, and beam-columns are discussed along with their potential failure modes.
Structural Connection Design & Construction Aspect .pptxahmad705917
Structural connection design and constructability are discussed. Connections are critical for transferring forces between structural members safely and economically. Simple bolted connections are commonly used due to ease of fabrication and ability to accommodate site adjustments. Connection types include shear, moment, and splice connections. Failure modes like bolt shear, bearing, and block shear are reviewed. Constructability considerations include connection design for simplicity and repetition to reduce erection costs.
This presentation was developed as a teaching aid with the support of the American Institute of Steel Construction. Its objective is to provide technical background and information for bolting and welding. The information provided is based on common design and construction practices for structures of twelve stories or less.
This document provides an overview of considerations for jobsite layout and coordination for structural steel construction projects. It discusses factors like site size and configuration, building footprint, crane locations, laydown areas, access roads, underground utilities, worker parking, and facilities. The presentation emphasizes the importance of early coordination between the controlling contractor and steel contractor to finalize jobsite layout and sequencing plans. Proper planning of schedule, material delivery and erection processes is key to optimizing the structural steel construction process.
This brochure answers common questions about curved steel, such as who curves steel, where it can be used, and how the process works. It provides examples of projects that utilize curved steel, from airport canopies to entranceways. The document also includes step-by-step photographs explaining the rolling process used to bend steel beams. Engineers and architects are encouraged to contact steel bending specialists for help with unique bending needs or to better understand how to specify bending requirements in construction drawings.
This document discusses practical aspects of pre-stressed concrete (PSC) construction. It explains that PSC uses the intrinsic properties of steel and concrete, with concrete good for compression and steel for tension. Reinforcement is still needed in PSC for shear transfer, crack control, and stress distribution. Proper detailing and positioning of prestressing cables and reinforcement is important. Common issues in PSC construction include honeycombing, cracking, and stresses exceeding design limits. Solutions involve modified forms, grouting, additional reinforcement, and adjusted cable profiles. Proper material handling, stressing sequences, and construction methods are essential for successful PSC projects.
This presentation provides an overview of the construction process for a structural steel frame of a 4-story office building. It details the activities involved, including detailing, fabrication, transportation, and erection. Photographs and animations show the erection of the steel frame through its 6 sequenced phases. The overall goals are to introduce the user to the typical steps and provide technical insights into constructing a structural steel frame.
This document discusses design provisions for composite beams and columns. It covers general provisions, available strength calculations using plastic stress distribution and strain compatibility methods, design of encased composite columns, calculation of effective rigidity and nominal compressive strength, requirements for shear connectors, and design of built-up composite columns.
Multi-StageSheet Metal Fromed Bolted Fastener DesignMark Brooks
This document discusses the development of a multi-stage sheet metal fastening design that eliminates nuts to reduce costs and improve manufacturing efficiency. Testing showed that while extruded, rivet, and PEM nuts exceeded torque specifications, shear/tap fasteners only marginally met specifications, failing through thread tear. To breakthrough this technology barrier, the basics of thread forming were revisited. Roll-forming threads through compression may improve performance over cutting threads.
Steel structures are made from combinations of structural steel members designed to carry loads and provide rigidity. Common steel structures include buildings, bridges, and towers. Steel comes in various grades depending on carbon content, including low carbon steel (mild steel), medium carbon steel, and high carbon steel. Steel structures offer advantages like strength, light weight, and ease of fabrication but require maintenance to prevent corrosion. Common steel sections used in construction include I-beams, channels, angles, and hollow sections. Connections between steel members can be welded, bolted, or riveted.
This document discusses design provisions for composite beams and columns. It covers general provisions, available strength calculation methods, encased composite column design including buckling strength calculations, requirements for shear connectors between the steel section and concrete encasement, and provisions for built-up composite columns. Design equations are provided for nominal strength, effective rigidity, equivalent shear force, and shear strength of connectors.
This document provides an introduction to prestressed concrete, including:
- Prestressing concrete involves applying an initial compressive load to counteract tensile stresses during use. Ancient examples include metal bands on wood.
- Prestressing provides advantages over reinforced concrete like reduced cracking, increased strength and stiffness, and suitability for precast construction.
- It describes prestressing materials, common systems like pre-tensioning and post-tensioning, and concepts in the analysis and design of prestressed concrete like stress conditions and load balancing.
Lecture 3-Composites construction (1).pptxanik7nziza
This document discusses composite construction techniques, specifically composite metal decking with concrete and concrete-cambering composites. It describes how composite metal decking works with concrete fill to create a stiff, lightweight floor system. Methods for installing metal decking, shear connectors, and concrete are outlined. Cambering steel beams is discussed as a method to compensate for beam deflection under wet concrete loads. Quality control procedures for shear connector installation and verifying proper camber are also summarized.
This document provides guidelines for designing and detailing steel column base plates. It discusses considerations for base plate materials, fabrication, and erection. For materials, it recommends commonly available grades like A36 steel for plates and A307 or A449 bolts. It suggests design approaches that are easier to fabricate, like using thicker base plates to eliminate stiffeners. For erection, it identifies potential problems like mislocated anchor bolts and provides tips to prevent issues. The document aims to provide practical guidance to engineers, fabricators, and contractors for designing base plates that are economical to fabricate and erect.
These slides gives a basic idea about R C C structures. Elementary knowledge about different methods of design and detailing as IS code IS 456-2000 has been discussed in a lucid way.
Similar to 111562940 aisc-bolting-and-welding-190606215451 (20)
Communications Mining Series - Zero to Hero - Session 1DianaGray10
This session provides introduction to UiPath Communication Mining, importance and platform overview. You will acquire a good understand of the phases in Communication Mining as we go over the platform with you. Topics covered:
• Communication Mining Overview
• Why is it important?
• How can it help today’s business and the benefits
• Phases in Communication Mining
• Demo on Platform overview
• Q/A
Climate Impact of Software Testing at Nordic Testing DaysKari Kakkonen
My slides at Nordic Testing Days 6.6.2024
Climate impact / sustainability of software testing discussed on the talk. ICT and testing must carry their part of global responsibility to help with the climat warming. We can minimize the carbon footprint but we can also have a carbon handprint, a positive impact on the climate. Quality characteristics can be added with sustainability, and then measured continuously. Test environments can be used less, and in smaller scale and on demand. Test techniques can be used in optimizing or minimizing number of tests. Test automation can be used to speed up testing.
Building Production Ready Search Pipelines with Spark and MilvusZilliz
Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
AI 101: An Introduction to the Basics and Impact of Artificial IntelligenceIndexBug
Imagine a world where machines not only perform tasks but also learn, adapt, and make decisions. This is the promise of Artificial Intelligence (AI), a technology that's not just enhancing our lives but revolutionizing entire industries.
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
Best 20 SEO Techniques To Improve Website Visibility In SERPPixlogix Infotech
Boost your website's visibility with proven SEO techniques! Our latest blog dives into essential strategies to enhance your online presence, increase traffic, and rank higher on search engines. From keyword optimization to quality content creation, learn how to make your site stand out in the crowded digital landscape. Discover actionable tips and expert insights to elevate your SEO game.
Pushing the limits of ePRTC: 100ns holdover for 100 daysAdtran
At WSTS 2024, Alon Stern explored the topic of parametric holdover and explained how recent research findings can be implemented in real-world PNT networks to achieve 100 nanoseconds of accuracy for up to 100 days.
GraphSummit Singapore | The Future of Agility: Supercharging Digital Transfor...Neo4j
Leonard Jayamohan, Partner & Generative AI Lead, Deloitte
This keynote will reveal how Deloitte leverages Neo4j’s graph power for groundbreaking digital twin solutions, achieving a staggering 100x performance boost. Discover the essential role knowledge graphs play in successful generative AI implementations. Plus, get an exclusive look at an innovative Neo4j + Generative AI solution Deloitte is developing in-house.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und überflüssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/building-and-scaling-ai-applications-with-the-nx-ai-manager-a-presentation-from-network-optix/
Robin van Emden, Senior Director of Data Science at Network Optix, presents the “Building and Scaling AI Applications with the Nx AI Manager,” tutorial at the May 2024 Embedded Vision Summit.
In this presentation, van Emden covers the basics of scaling edge AI solutions using the Nx tool kit. He emphasizes the process of developing AI models and deploying them globally. He also showcases the conversion of AI models and the creation of effective edge AI pipelines, with a focus on pre-processing, model conversion, selecting the appropriate inference engine for the target hardware and post-processing.
van Emden shows how Nx can simplify the developer’s life and facilitate a rapid transition from concept to production-ready applications.He provides valuable insights into developing scalable and efficient edge AI solutions, with a strong focus on practical implementation.
Threats to mobile devices are more prevalent and increasing in scope and complexity. Users of mobile devices desire to take full advantage of the features
available on those devices, but many of the features provide convenience and capability but sacrifice security. This best practices guide outlines steps the users can take to better protect personal devices and information.
Maruthi Prithivirajan, Head of ASEAN & IN Solution Architecture, Neo4j
Get an inside look at the latest Neo4j innovations that enable relationship-driven intelligence at scale. Learn more about the newest cloud integrations and product enhancements that make Neo4j an essential choice for developers building apps with interconnected data and generative AI.
2. Introduction
This presentation was developed as a teaching aid with the support of the
American Institute of Steel Construction. Its objective is to provide technical
background and information for bolting and welding. The information
id d i b d d i d t ti ti f
provided is based on common design and construction practices for
structures of twelve stories or less.
The AISC Digital Library case study presentations document the construction
The AISC Digital Library case study presentations document the construction
of a steel frame for an office building. The case study includes photographs
that were taken throughout the construction of the structural steel frame
including detailing fabrication and erection Project data including plans
including detailing, fabrication, and erection. Project data including plans,
schedules, specifications and other details are also included. The case study
presentations are available in the Learning Opportunities section at
www aisc org
www.aisc.org.
This presentation provides technical information on bolting and welding, as
well as the impacts of details and design choices on schedule, cost,
well as the impacts of details and design choices on schedule, cost,
sequence and overall project management.
The information is presented with concerns of a construction manager or
2
p g
general contractor in mind.
3. What Will You Gain From This
P t ti ?
Presentation?
• General knowledge of structural steel
A d t di f th diff t th t t t l t l i t d
• An understanding of the different ways that structural steel is connected
• Insight into types of bolts and their installation
• An awareness of types of bolted joints used for structural steel
• Knowledge of welding terminology, weld types, and welding processes
• Familiarity with common weld inspection methods and considerations
associated with field welding
3
4. Benefits of Structural Steel
Some benefits associated with use of structural steel for owners are:
• Steel allows for reduced frame construction time and the ability to construct
in all seasons
• Steel makes large spans and bay sizes possible, providing more flexibility for
owners
owners
• Steel is easier to modify and reinforce if architectural changes are made to a
facility over its life
4
• Steel is lightweight and can reduce foundation costs
• Steel is durable, long-lasting and recyclable (AISC 1999)
5. Unique Aspects of Steel Construction
Procurement and management of structural steel is similar to other materials,
but there are some unique aspects to steel construction:
• Steel is fabricated off-site (above left)
• On-site erection is a rapid process (above right)
• This gives use of structural steel some scheduling advantages
5
• Coordination of all parties is essential for achieving potential advantages
(AISC 1999)
6. Connecting Structural Steel
• The primary connection methods for structural steel are bolting and welding
• A structure’s strength depends on proper use of these connection methods
• Connections made in a fabrication shop are called shop connections
6
• Connections made in the field by the steel erector are called field connections
• Bolting and welding may be used for shop connections and field connections
7. Connecting Structural Steel
• A fabrication shop will have a desired fastening method suited to its equipment
and fabrication methods
• Field connections are typically bolted
• Welding may be used for field connections where bolting is either impractical or
ndesirable
7
undesirable
• Welding is better suited to the controlled environment of a fabrication shop
9. Structural Bolting
• The Research Council on Structural Connections (RCSC) prepares
The Research Council on Structural Connections (RCSC) prepares
specifications and documents related to structural connections
• RCSC’s Specification for Structural Joints Using ASTM A325 or A490 Bolts
(2000) is a widely used specification which discusses joints fasteners limit
9
(2000) is a widely used specification which discusses joints, fasteners, limit
states, installation, and inspections
10. Structural Bolting
• During hoisting, connectors will install a minimum of two bolts per connection
• The rest of the bolts are installed and tightened after the structure is plumbed
• A systematic pattern must be followed when tightening bolts so that a joint is
10
drawn together and all fasteners are properly installed
(SSTC 2001)
11. Structural Bolting
Per the Occupational Safety & Health Administration Standard 1926.754(b)(2), “At
no time shall there be more than four floors or 48 feet (14.6 m), whichever is less,
f fi i h d b lti ldi b th f d ti t tl
11
of unfinished bolting or welding above the foundation or uppermost permanently
secured floor, except where the structural integrity is maintained as a result of the
design.”
12. Structural Bolting
(AISC & NISD 2000)
• There are many bolt types, installation methods, and joint types used in
structural steel construction
12
• When left exposed, bolts may be used to make an architectural expression
(Green, Sputo, and Veltri)
13. ASTM Bolt Types
(AISC & NISD 2000)
• A307 – Low carbon steel
Not commonly used
Not commonly used
Only used for secondary members
• A325 – High-strength medium carbon steel (above left)
A325 High strength medium carbon steel (above left)
Most common bolts used in building construction
• A490 – High-strength heat treated steel (above right)
13
Cost more than A325’s, but are stronger so fewer bolts may be necessary
• Note that the ASTM designation is indicated on the head of the bolts above
14. Common Bolt Sizes
• A325 and A490 bolts are available in diameters ranging from 1/2” to 1-1/2”
• The most common sizes are 3/4”, 7/8”, and 1”
14
• High-strength bolts are commonly available in incremental lengths up to 8”
(AISC)
15. Washers
• Hardened steel washers are used in many structural connections to spread
pressure from the bolt tightening process over a larger area
• Washers may also be used to cover an oversized or slotted hole (RCSC 2000)
• Flat washers are most commonly used
• Tapered washers (above left) are used when the surface being bolted has a
sloped surface, such as the flange of a channel or an S shape
• A325 bolts require a washer under the element (head or nut) being turned to
15
A325 bolts require a washer under the element (head or nut) being turned to
tighten the bolt (shown under the nut, above right)
• A490 bolts require a washer under both the head and nut (AISC & NISD 2000)
16. Parts of the Bolt Assembly
Grip Washer
Nut
Washer
Face
Grip
Shank Thread
Head
Thread
Length
• Grip is the distance from behind the bolt head to the back of the nut or washer
It is the sum of the thicknesses of all the parts being joined exclusive of
It is the sum of the thicknesses of all the parts being joined exclusive of
washers
• Thread length is the threaded portion of the bolt
16
• Bolt length is the distance from behind the bolt head to the end of the bolt
(AISC & NISD 2000)
17. Bolted Joint Types
• There two basic bolted joint types:
Bearing
o The load is transferred between members by bearing on the bolts
17
Slip-critical
o The load is transferred between members by friction in the joint
18. Bolted Joint Failure Modes
Bearing
B i Bearing Bearing
Fracture
Bearing
Yield
Bearing
Fracture
Bearing
Yield
• Bolts in bearing joints are designed to meet two limit states:
Yield
1. Yielding, which is an inelastic deformation (above left)
2. Fracture, which is a failure of the joint (above left)
Th t i l th b lt b i t i l bj t t i ldi f t if it i
• The material the bolt bears against is also subject to yielding or fracture if it is
undersized for the load (above right)
• Tension connections act similarly to bearing connections
18
y g
Many times, connections in direct tension are reconfigured so that the bolts
act in shear (AISC)
19. Bearing Joints
• In a bearing joint the connected elements are assumed to slip into bearing
against the body of the bolt
19
against the body of the bolt
• If the joint is designed as a bearing joint the load is transferred through bearing
whether the bolt is installed snug-tight or pretensioned (AISC)
20. Th h l i th l
Threads in the Shear Plane
• The shear plane is the plane
between two or more pieces
under load where the pieces
tend to move parallel from
tend to move parallel from
each other, but in opposite
directions
• The threads of a bolt may
either be included in the
shear plane or excluded
Threads Included In The Shear Plane
from the shear plane
• The capacity of a bolt is
greater with the threads
Threads Included In The Shear Plane
g eate t t e t eads
excluded from the shear
plane
• The most commonly used
• The most commonly used
bolt is an ASTM A325 3/4”
bolt with the threads
included in the shear plane
20
included in the shear plane
(AISC & NISD 2000)
Threads Excluded From The Shear Plane
21. Slip-Critical Joints
• In a slip-critical joint the bolts must be fully pretensioned to cause a clamping
force between the connected elements
• This force develops frictional resistance between the connected elements
• The frictional resistance allows the joint to withstand loading without slipping
into bearing against the body of the bolt, although the bolts must still be
21
into bearing against the body of the bolt, although the bolts must still be
designed for bearing
• The faying surfaces in slip-critical joints require special preparation (AISC)
22. When to Use Slip-Critical Joints
Per the RCSC Specification (2000), Slip-critical joints are only required in the
following applications involving shear or combined shear and tension:
1. Joints that are subject to fatigue load with reversal of the loading direction
(not applicable to wind bracing)
2 J i t th t tili i d h l
2. Joints that utilize oversized holes
3. Joints that utilize slotted holes, except those with applied load approximately
perpendicular to the direction of the long dimension of the slot
22
p p g
4. Joints in which slip at the faying surfaces would be detrimental to the
performance of the structure
23. Snug-tight Installation
Snug-tight is the tightness attained with a few hits of an impact wrench or the full
effort of an ironworker using an ordinary spud wrench to bring the connected plies
23
g y p g p
into firm contact
(RCSC 2000)
24. Turn-of-Nut Installation
• Installation beyond snug-tight is called pretensioning
• Turn-of-nut pretensioning involves several steps:
p g p
1. The bolt is snug-tightened
2. Matchmarks are placed on each nut, bolt, and steel surface in a straight line
p g
3. The part not turned by the wrench is prevented from turning
4. The bolt is tightened with a prescribed rotation past the snug-tight condition
24
• The specified rotation varies by diameter and length (between 1/3 and 1 turn)
(RCSC 2000, AISC)
25. Calibrated Wrench Installation
• Calibrated Wrench pretensioning uses an impact wrench (above left) to tighten
th b lt t ifi d t i
the bolt to a specified tension
• A Skidmore-Wilhelm calibration device (above right) is used to calibrate the
impact wrench to the torque level which will achieve the specified tension
25
p q p
• A sample of bolts representative of those to be used in the connections are
tested to verify that the correct tension will be achieved (RCSC 2000, AISC)
26. ASTM F1852 Installation
(AISC)
• F1852 bolts are twist-off-type tension-
control bolts
• These bolts must be pretensioned with a
twist-off-type tension-control bolt installation
wrench that has two coaxial chucks
• The inner chuck engages the splined end of
the bolt
The o ter ch ck engages the n t
• The outer chuck engages the nut
• The two chucks turn opposite to one
another to tighten the bolt
26
• The splined end of the F1852 bolt shears
off at a specified tension (AISC 2003)
27. ASTM F959 Direct Tension Indicators
DTI’s
DTI s
• Another way to try to ensure proper pretensioning of a bolt is through the use of
di t t i i di t (DTI )
Feeler Gages
direct tension indicators (DTIs)
• These washers have protrusions that must bear against the unturned element
• As the bolt is tightened the clamping force flattens the protrusions and reduces
• As the bolt is tightened the clamping force flattens the protrusions and reduces
the gap
• The gap is measured with a feeler gage
27
• When the gap reaches the specified size the bolt is properly pretensioned
(AISC & NISD 2000)
28. Installation of DTIs
(Adapted from Figure C 8 1 RCSC 2000)
It is essential that direct tension indicators be properly oriented in the assembly
a) The bolt head is stationary while the nut is turned DTI under bolt head
(Adapted from Figure C-8.1 RCSC 2000)
a) The bolt head is stationary while the nut is turned – DTI under bolt head
b) The bolt head is stationary while the nut is turned – DTI under nut (washer required)
c) The nut is stationary while the bolt head is turned – DTI under bolt head (washer required)
28
d) The nut is stationary while the bolt head is turned – DTI under nut
(RCSC 2000)
29. Nominal Bolt Hole Dimensions
• Bolts are installed in one of four types of holes (see table above)
(Table 3.1 RCSC 2000)
• Standard holes can be used anywhere
• Oversized holes may only be used in slip-critical connections
29
• Short-slotted holes are used with the slot perpendicular to the direction of stress
• Long-slotted holes are primarily used when connecting to existing structures
30. Equipment Requirements
• Common tools used by Ironworkers include spud wrenches, pins, and
corrections bars of various sizes (above left)
corrections bars of various sizes (above left)
• Impact wrenches will be needed for certain installations (above center)
• Electricity or compressed air is required depending on the impact wrench being
30
Electricity or compressed air is required depending on the impact wrench being
used
A generator as well as an air compressor may be needed (above right)
31. Storage of Components
Per the RCSC Specification:
• Fastener components must be protected from dirt and moisture in closed
containers on the jobsite
O l f t ti i t d t b i t ll d d i th k hift t b t k
• Only fasteners anticipated to be installed during the work shift are to be taken
from protected storage
• Protected storage is defined as the continuous protection of fastener
31
g p
components in closed containers in a protected shelter
• Any unused fasteners must be promptly returned to protected storage
32. Storage of Components
Th l b i ti f t i it l t th i i t ll ti
• The lubrication on fasteners is vital to their proper installation
• A water-soluble oil is used on most black bolts
This oil is easily washed off when exposed to moisture
• This oil is easily washed off when exposed to moisture
• Fasteners that accumulate rust or dirt must be cleaned and relubricated before
they may be installed
32
• F1852 bolts (shown above) shall not be relubricated, except by the
manufacturer (RCSC 2000, SSTC 2001)
33. Storage of Galvanized Fasteners
• Galvanized bolts and nuts (above) are provided by the supplier in a set and
Ga a ed bo ts a d uts (abo e) a e p o ded by t e supp e a set a d
special storage requirements
• Each bolt/nut set is pretested by the supplier and shipped together and must be
kept together as an assembly
kept together as an assembly
• Poor thread fit may result if the bolt and nut are mismatched
• The lubrication on galvanized fasteners is generally more durable than that on
33
• The lubrication on galvanized fasteners is generally more durable than that on
black bolts, but protected storage is still recommended
• A490 bolts are not allowed to be galvanized (SSTC 2001)
34. Production Lots
• Production lot traceability is required by many standards
• Even if not required, it is good practice to record the lot numbers and keep all
fasteners separated by lot
fasteners separated by lot
• It is necessary to keep lots separate for proper pre-installation verification
testing which is required for pretensioned and slip-critical joints
34
• Mixing bolts and nuts from different production lots is not permitted
(SSTC 2001)
35. Inspections
• In addition to the erector’s quality control program, tests and inspection are
specified by the Engineer of Record and/or the local building authority
• A local building inspector may request that tests in addition to those specified
A local building inspector may request that tests in addition to those specified
by the Engineer of Record be performed
• Snug-tightened joints require visual inspection for firm contact and proper use
f h
of washers
• Pretensioned joints require pre-installation verification and routine observation
of proper application
35
p p pp
• Slip-critical joints require inspection of the faying surfaces in addition to the
above inspections
36. Inspections for the Construction Manager
There are several bolted connection inspections a construction manager can
p g
perform:
• Look at the bolt stick-out (above)
Sti k t i th t th b lt t d b d th t id f f th
Stick-out is the amount the bolt extends beyond the outside surface of the
nut
Positive or zero stick-out is acceptable
36
p
Negative stick-out, where the end of the bolt is inside the nut, is not
acceptable
37. Inspections for the Construction Manager
• Inspect the turn-of-nut matchmarks to ensure the bolts have been pretensioned
• If F1852 bolts are used, make sure the ends have been snapped off all bolts
(above)
In some cases due to insufficient clearance for the installation wrench
37
In some cases, due to insufficient clearance for the installation wrench,
F1852 bolts will be tightened by alternative methods so the ends will not be
snapped off
38. Bolting Cost Considerations
The types of joints used in a structure are somewhat dependent on the overall
design of the structure, but these are some points to consider:
• The erector may prefer certain bolt and joint types over others due to
equipment requirements, experience, and installation times
S ti ht d j i t ll th t i l b lt d j i t (R b
design of the structure, but these are some points to consider:
• Snug-tightened joints are normally the most economical bolted joints (Ruby
2003)
• For pretensioned joints, F1852’s and DTI’s are popular and can be economical
38
p j , p p
• Slip-critical joints are the most costly joints, and should only be specified when
necessary (Ruby 2003)
40. Structural Welding
• Another common method for connecting structural steel is welding
• Welding can be performed in the shop or in the field
• Welding can be performed in the shop or in the field
• Many fabrication shops prefer to weld rather than bolt
• Welding in the field is avoided if possible due to welding condition requirements
40
Welding in the field is avoided if possible due to welding condition requirements
• There are several welding processes, types, and positions to be considered in
building construction
41. Structural Welding
• The American Welding Society (AWS) is a nonprofit organization with a goal to
advance the science, technology and application of welding and related joining
di i li
disciplines
• AWS develops codes, recommended practices, and guides under strict
American National Standards Institute (ANSI) procedures
41
( ) p
• D1.1 Structural Welding Code – Steel, one of the most consulted codes in the
world, is produced by AWS (AWS 2004a)
42. Structural Welding
• Welding is the process of fusing multiple pieces of metal together by heating
42
Welding is the process of fusing multiple pieces of metal together by heating
the filler metal to a liquid state
• A properly welded joint is stronger than the base metal
43. Strength of Structural Welds
(Part of Table J2.5 AISC 2005)
• Welds may be loaded in shear, tension, compression, or a combination of these
• Capacities for welds are given in the AISC Specification Section J2 (2005)
43
• The strength of a weld is dependent on multiple factors, including: base metal,
filler metal, type of weld, throat and weld size
44. Welding Terminology
• Tack Weld (above left)
A temporary weld used to hold parts in place while more extensive, final
welds are made
• Continuous Weld
Continuous Weld
A weld which extends continuously from one end of a joint to the other
• Stitch Weld (above right)
44
Stitch Weld (above right)
A series of welds of a specified length that are spaced a specified distance
from each other
45. Welding Terminology
Butt
Lap Corner
Tee
Edge
• Shown above are types of structural joints which are established by positions of
the connected material relative to one another
45
the connected material relative to one another
• Lap, tee, and butt joints are most common (AISC)
46. Welding Terminology
Fillet Full penetration
single bevel
groove weld
Partial penetration
single bevel
groove weld
groove weld groove weld
Full penetration Partial penetration
Plug
Full penetration
double vee
groove weld
Partial penetration
single J groove
weld
W ld t d fi th fi ti f th ld d it d l i d i
• Weld types define the configuration of the weld and its underlying design
approach
• Fillet welds and groove welds are most common
g
• Groove welds fall into two categories
Full penetration – the entire member cross-section is welded
46
Partial penetration – just part of the member cross-section is welded
(AISC)
47. Fillet Welds
Symbolic Profiles
Symbolic Profiles
Actual Profiles
• The most commonly used weld is the fillet weld
• Fillet welds are theoretically triangular in cross-section
• Fillet welds join two surfaces at approximately right angles to each other in lap,
tee and corner joints
47
tee, and corner joints
(AISC & NISD 2000)
48. Groove Welds
• Groove welds are specified when a fillet weld is not appropriate for the job
The configuration of the pieces may not permit fillet welding
A strength greater than that provided by a fillet weld is required
48
• Groove welds are made in the space or groove between the two pieces being
welded (AISC & NISD 2000)
49. Full Penetration Groove Welds
• The bevel or “J” preparation extends over most of or the entire face of the
p p
material being joined
• Complete fusion takes place
49
• In some types of full penetration groove welds the material will be beveled from
one side of the plate with a separate plate on the opposite side – called backing
or a backing bar (AISC & NISD 2000)
50. Partial Penetration Groove Welds
Partial joint penetration welds are used when it is not necessary for the strength of
50
Partial joint penetration welds are used when it is not necessary for the strength of
the joint to develop the full cross section of the members being joined
(AISC & NISD 2000)
51. Welding Positions
• There are four recognized welding positions:
Fl t Th f f th ld i i t l h i t l d ldi i
Flat – The face of the weld is approximately horizontal and welding is
performed from above the joint
Horizontal – The axis of the weld is horizontal
Vertical – The axis is approximately vertical or in the upright position
Overhead – Welding is performed from below the joint
51
• The flat position is preferred because it is easier and more efficient to weld in
this position (AISC & NISD 2000)
52. • Weld symbols are used
Weld Symbols
Weld symbols are used
to communicate the
specific details and
requirements of each
equ e e ts o eac
weld to the welder
• Weld symbols are
included on fabrication
included on fabrication
and erection drawings
Horizontal Weld Line
Horizontal Weld Line
Tail
Note
(Indicating this is
Field Weld Symbol
Leader Line
(Indicating this is
a typical weld)
Length and Spacing of weld
(In Inches)
Size of weld
52
Basic Weld Symbol
(Fillet weld symbol shown)
Size of weld
(In Inches)
53. Weld Size
• The size of a weld must match the size specified on the drawings
• Some welds may meet the required size after a single pass of the welder
• Larger weld sizes may require multiple passes to meet the size requirement
• Common single pass welds include fillet welds up to and including 5/16 inch
and thin plate butt welds with no preparation
• Common multiple pass welds include single bevel full penetration groove welds
53
• Common multiple pass welds include single bevel full penetration groove welds,
single bevel partial penetration groove welds, and fillet welds over 5/16 inch
• The weld in the above picture is a multiple pass fillet weld
54. Weld Accessibility
• Access holes are required for
Access holes are required for
some welds, such as the welded
flange connection shown to the
right
Extension Bar
right
The top access hole allows
for a continuous backing
bar to be placed under the
bar to be placed under the
top flange
The bottom access hole
ll f l t
Column
Weld Access
H l
Backing Bar
allows for complete access
to weld the entire width of
the bottom flange
n
Holes
• A detail of a weld access hole
for a welded flange connection
is shown below
Seat Angle
54
(Adapted from AISC 2001)
(Adapted from AISC 2002a)
55. SMAW Welding
• Shielded Metal Arc Welding (SMAW) is also known as manual, stick, or hand
welding
• An electric arc is produced between the end of a coated metal electrode and
the steel components to be welded
• The electrode is a filler metal covered with a coating
The electrode is a filler metal covered with a coating
• The electrode’s coating has two purposes:
• It forms a gas shield to prevent impurities in the atmosphere from getting
55
g p p p g g
into the weld
• It contains a flux that purifies the molten metal (AISC & NISD 2000)
56. GMAW Welding
G M t l A W ldi (GMAW) i l k MIG ldi
• Gas Metal Arc Welding (GMAW) is also known as MIG welding
• It is fast and economical
• A continuous wire is fed into the welding gun
A continuous wire is fed into the welding gun
• The wire melts and combines with the base metal to form the weld
• The molten metal is protected from the atmosphere by a gas shield which is fed
56
through a conduit to the tip of the welding gun
• This process may be automated (AISC & NISD 2000)
57. FCAW Welding
• Flux Cored Arc Welding (FCAW) is similar to the GMAW process
• The difference is that the filler wire has a center core which contains flux
• With this process it is possible to weld with or without a shielding gas
This makes it useful for exposed conditions where a shielding gas may be
57
affected by the wind
(AISC & NISD 2000)
58. SAW Welding
S b d A W ldi (SAW) i l f d b t ti
• Submerged Arc Welding (SAW) is only performed by automatic or
semiautomatic methods
• Uses a continuously fed filler metal electrode
y
• The weld pool is protected from the surrounding atmosphere by a blanket of
granular flux fed at the welding gun
58
• Results in a deeper weld penetration than the other process
• Only flat or horizontal positions may be used (AISC & NISD 2000)
59. Welding Equipment
• Equipment used for welding will vary depending on the welding process and
whether the welding is being done in the shop or in the field
59
• A Flux Cored Arc Welding machine for shop welding is pictured above left
• A Shielded Metal Arc Welding machine for field welding is pictured above right
60. Weather Impacts on Welding
• Welding in the field is avoided if possible due to welding condition requirements
• Field welding is not to be performed while it is raining, snowing, or below 0° F
g p g, g,
• In certain ambient temperatures preheating of the material to be welded is
required
60
• AWS Code D1.1 (2004b) specifies minimum preheat and interpass
temperatures, which are designed to prevent cracking
61. Welding Safety
• It is important for both the welder and those working in the area around a
welding process to be safety conscious
• The welding arc should never be looked at with the naked eye
61
The welding arc should never be looked at with the naked eye
• AWS publishes many safety and health fact sheets which are available for
download at their web site: www.aws.org
62. Welding Safety
A welder should wear the proper protective gear including:
• Helmet
• Face shield or goggles
• Heavy fabric or leather shirt
• Cuffless pants
62
• Gloves
• Boots
• Leather leggings
63. Welding in Existing Structures
Welding to existing structures during retrofit projects requires careful consideration
Welding to existing structures during retrofit projects requires careful consideration
of numerous factors:
• Determine weldability – Identify the steel grade to establish a welding
procedure
p
• Select and design the weld – Fillet welds are preferred and avoid over welding
• Surface preparation – Remove contaminants such as paint, oil, and grease
• Loads during retrofit – An engineer should determine the extent to which a
member will be permitted to carry loads while heating, welding, or cutting
• Fire hazards – Follow all governing fire codes regulations and safety rules to
63
Fire hazards Follow all governing fire codes, regulations, and safety rules to
avoid fires
• For complete details see the AISC Rehabilitation and Retrofit Guide (2002b)
64. Weld Inspections
• In addition to the erector’s quality control program, tests and inspections are
specified by the Engineer of Record and/or the local building authority
specified by the Engineer of Record and/or the local building authority
• A local building inspector may request that tests in addition to those specified
by the Engineer of Record be performed
• Some problems that can be found in welds include:
Lack of fusion Cracks Wrong size
64
Porosity Insufficient penetration
• There are several weld tests and inspections that are commonly used
Poor workmanship
65. Visual Inspection
• Visual inspection is the most frequently used inspection and is the only
sua spect o s t e ost eque t y used spect o a d s t e o y
inspection required unless the specification calls for a more stringent inspection
method
• Inspection is done by the welder before during and after welding
• Inspection is done by the welder before, during, and after welding
• When outside inspection is required it should also be done before, during, and
after welding
65
• Minor problems can be identified and corrected before the weld is complete
(AISC & NISD 2000)
66. Dye Penetrant Test
• Dye penetrant testing locates minute surface cracks and porosity
• Dye types that may be used include:
y yp y
Color contrast dye - which shows up under ordinary light
Fluorescent dye – which shows up under black light
66
• The dye is normally applied by spraying it directly on the weld
(AISC & NISD 2000)
67. Magnetic Particle Inspection
• Magnetic particle inspection uses powdered magnetic particles to indicate
• Magnetic particle inspection uses powdered magnetic particles to indicate
defects in magnetic materials
• A magnetic field is induced in the part
67
• The magnetic powder is attracted to and outlines cracks within the material
(AISC & NISD 2000)
68. Ultrasonic Inspection
• Ultrasonic inspection can be used to detect flaws inside welds
• High frequency sound waves are directed into the metal with a probe held at a
specific angle
specific angle
• The flaws reflect some energy back to the probe
• Flaws show up as indications on a screen (above) and are subject to
68
• Flaws show up as indications on a screen (above) and are subject to
interpretation by an inspector
(AISC & NISD 2000)
69. Radiographic Inspection
• Radiographic inspection or X ray can also be used to detect flaws inside welds
• Radiographic inspection, or X-ray, can also be used to detect flaws inside welds
• Invisible rays penetrate the metal and reveal flaws on an x-ray film or
fluorescent screen (above)
69
• This is the most costly of the inspection methods
(AISC & NISD 2000)
70. Welding Cost Considerations
• Fillet weld is less expensive than groove weld
Fillet weld is less expensive than groove weld
No special preparation
No backing required
No backing required
Less volume of weld
• Partial penetration groove weld is less expensive than full
70
p g p
penetration groove weld
• Labor represents the majority of the cost associated with welding
71. Bolting and Welding
Scheduling Considerations
Scheduling Considerations
• Bolting is generally a faster operation than welding
g g y p g
• Bolting does not have the temperature and weather condition requirements that
are associated with welding
71
• Unexpected weather changes may delay welding operations
73. References
AISC. (n.d.). Steel Connections: Behavior and Practice [35mm Slide Show with Script].
American Institute of Steel Construction, Inc. Chicago, IL.
AISC. (2001). LRFD Manual of Steel Construction, Third Edition. American Institute of Steel
Construction Inc Chicago IL
Construction, Inc. Chicago, IL.
AISC. (2002a). Seismic Provisions for Structural Steel Buildings. American Institute of Steel
Construction, Inc. Chicago, IL.
AISC. (2002b). Design Guide 15 – AISC Rehabilitation and Retrofit Guide. American Institute of
( ) g
Steel Construction, Inc. Chicago, IL.
AISC. (2003). High Strength Bolts: A Primer for Structural Engineers. American Institute of Steel
Construction, Inc. Chicago, IL.
AISC & NISD (2000) D t il T i i S i [CD ROM t] A i I tit t f St l
AISC & NISD. (2000). Detailer Training Series [CD-ROM set]. American Institute of Steel
Construction, Inc. and National Institute of Steel Detailing. Chicago, IL. (Available from
AISC, One East Wacker Drive, Suite 3100, Chicago, IL 60601).
American Welding Society, (AWS). (2004a). American Welding Society Web Site. Available at:
g y, ( ) ( ) g y
http://www.aws.org/. Viewed August, 2004.
American Welding Society, (AWS). (2004b). “Structural Welding Code.” ANSI/AWS D1.1-2004,
Miami, FL.
G P S S t T d V lt i P ( d ) C ti T hi T lkit A T hi G id
Green, P. S., Sputo, T., and Veltri, P. (n.d.). Connections Teaching Toolkit – A Teaching Guide
for Structural Steel Connections. American Institute of Steel Construction, Inc. Chicago, IL.
Research Council on Structural Connections, (RCSC). (2000). Specification for Structural Joints
Using ASTM A325 or A490 Bolts. American Institute of Steel Construction, Inc. Chicago, IL.
73
g , g ,
Ruby, D.I. (2003) . “All About Bolts.” AISC Modern Steel Construction, May.
SSTC. (2001). Structural Bolting Handbook. Steel Structures Technology Center, Inc. Novi, MI.