This document discusses machining forces and Merchant's Circle Diagram (MCD). It begins by explaining the importance and purposes of determining cutting forces. It then describes the different cutting force components for turning, drilling and milling operations. Next, it introduces MCD and how it can be used to represent cutting forces and their relationships. The document provides examples of how MCD can be constructed and used to determine other forces, friction, shear strength, power consumption and more. It concludes by presenting solutions to example problems applying MCD calculations.
This document discusses the analysis of cutting forces in 2D orthogonal metal cutting using Merchant's circle theory. It introduces the mechanics of chip formation where a wedge-shaped tool shears metal along the primary shear plane at an angle (φ). Merchant's circle relates the shear angle (φ), rake angle (α), and friction angle (λ) and can be used to calculate cutting and thrust forces. The maximum shear stress theory states that the shear angle is selected to minimize the energy of cutting and is calculated based on α, λ, and an assumption that the material behaves plastically. Key cutting force relationships and assumptions of Merchant's model are also outlined.
The document discusses the Merchant's Circle model for orthogonal metal cutting. It outlines assumptions of the model including a perfectly sharp tool, no contact between tool flank and workpiece, and uniform stress on the shear plane. It describes forces on the chip during cutting, including the force exerted by the tool on the chip (R), its components (N and F), and the resulting cutting force (Fc) and thrust force (Ft) on the tool. The model views the chip as a rigid body in constant motion with zero acceleration, so the forces R and R' acting on it are equal in magnitude but opposite in direction.
This document provides an overview of mechanics of machining and Merchant's circle diagram (MCD). It introduces metal cutting, tool geometry, assumptions for force analysis, and forces acting on single point cutting tools. Key points include shear plane analysis using rake and shear angles, assumptions of orthogonal cutting and constant chip thickness. Construction of the MCD is described to relate cutting, thrust and feed forces. The MCD allows calculation of shear stress, power and friction coefficient, enabling selection of machine parameters and tool/workpiece design.
This document discusses orthogonal and oblique cutting operations in turning. It defines:
- Orthogonal cutting as having the cutting edge travel perpendicular to the workpiece with perpendicular cutting forces.
- Oblique cutting as having the cutting edge travel at an angle to the workpiece normal with three mutually perpendicular forces.
It provides diagrams of the forces acting in orthogonal and oblique cutting. Key forces defined are feed force, radial force, and cutting force. It also defines terms like rake angle, shear angle, chip thickness, cutting velocity, metal removal rate, specific energy, and machining time.
The document concludes with a sample problem asking to determine values like shear angle, friction coefficient, shear stresses and
This document discusses the analysis of cutting forces in 2D orthogonal metal cutting using Merchant's circle theory. It introduces the mechanics of chip formation where a wedge-shaped tool shears metal along the primary shear plane at an angle (φ). Merchant's circle relates the shear angle (φ), rake angle (α), and friction angle (λ) and can be used to calculate cutting and thrust forces. The maximum shear stress theory states that the shear angle is selected to minimize the energy of cutting and is calculated based on α, λ, and an assumption that the material behaves plastically. Key cutting force relationships and assumptions of Merchant's model are also outlined.
The document discusses the Merchant's Circle model for orthogonal metal cutting. It outlines assumptions of the model including a perfectly sharp tool, no contact between tool flank and workpiece, and uniform stress on the shear plane. It describes forces on the chip during cutting, including the force exerted by the tool on the chip (R), its components (N and F), and the resulting cutting force (Fc) and thrust force (Ft) on the tool. The model views the chip as a rigid body in constant motion with zero acceleration, so the forces R and R' acting on it are equal in magnitude but opposite in direction.
This document provides an overview of mechanics of machining and Merchant's circle diagram (MCD). It introduces metal cutting, tool geometry, assumptions for force analysis, and forces acting on single point cutting tools. Key points include shear plane analysis using rake and shear angles, assumptions of orthogonal cutting and constant chip thickness. Construction of the MCD is described to relate cutting, thrust and feed forces. The MCD allows calculation of shear stress, power and friction coefficient, enabling selection of machine parameters and tool/workpiece design.
This document discusses orthogonal and oblique cutting operations in turning. It defines:
- Orthogonal cutting as having the cutting edge travel perpendicular to the workpiece with perpendicular cutting forces.
- Oblique cutting as having the cutting edge travel at an angle to the workpiece normal with three mutually perpendicular forces.
It provides diagrams of the forces acting in orthogonal and oblique cutting. Key forces defined are feed force, radial force, and cutting force. It also defines terms like rake angle, shear angle, chip thickness, cutting velocity, metal removal rate, specific energy, and machining time.
The document concludes with a sample problem asking to determine values like shear angle, friction coefficient, shear stresses and
Cutting power & Energy Consideration in metal cuttingDushyant Kalchuri
Cutting power is an important parameter, especially in the case of rough operations, as it makes it possible to:
select and invest in a machine with a power output suited to the operation being carried out
obtain the cutting conditions that allow the machine's power to be used in the most effective way possible, so as to ensure optimal material removal rate while taking into account the capacity of the tool being used.
This document discusses tool geometry and signatures for single point cutting tools. It defines key tool angles such as rake angles, clearance angles, and cutting edge angles. Rake angles are provided for chip flow, while clearance angles avoid rubbing between the tool and workpiece. The document then explains ANSI tool signature standards and defines each element of a signature for a single point tool, including back rake angle, side rake angle, end and side relief angles, end and side cutting edge angles, and nose radius. An example signature of 0-7-6-8-15-16-0.8 is provided.
The document discusses cutting tool materials and Merchant's Circle Diagram (MCD) for calculating forces in machining. It provides information on 7 common cutting tool materials: high carbon steel, high speed steel, cast alloys, cemented carbides, coated carbides, ceramics, and diamonds. It also explains what MCD is and how it can be used graphically to calculate cutting, tangential, friction, normal, shear and normal shear forces from measured cutting forces. An example calculation using MCD is provided.
The document discusses machining processes and cutting tools. It provides definitions of machining and cutting tools. It describes:
- The importance of machining processes in manufacturing precise parts.
- Objectives of machining like high material removal rate and surface finish, low tool and power costs.
- Classification of cutting tools based on how relative motion is provided between tool and workpiece.
- Key terms related to cutting tool geometry like rake angle, relief angle, and their influence on tool strength and chip removal.
- Mechanism of chip formation and different types of chips produced.
Machining is any process in which a cutting tool is used to remove small chips of material from the workpiece (the workpiece is often called the "work"). To perform the operation, relative motion is required between the tool and the work.
signature of single point cutting toolVaibhav Kadu
This document discusses tool signatures and different tool geometry systems. It provides information on:
1) The objective is to explain tool signatures, how tool angles affect machining, and why understanding signatures is important.
2) Tool signatures specify the key angles of a cutting tool in a standardized way. They indicate the active angles during cutting.
3) Three common tool geometry systems are described - ASA, ORS, and NRS. They each define tool angles differently based on different reference planes.
This document discusses mechanics of metal cutting. It covers topics like cutting models, forces, energies, and material removal rate. The orthogonal cutting model is described, which assumes a straight cutting edge generating a plane surface. Key terms like rake angle, shear angle, and cutting forces are defined. The relationships between cutting parameters, forces, power, and specific cutting energy are explained using the orthogonal model. Limitations of this simplified model are also noted.
cutting forces(static) simulation on latheTaliya Hemanth
This document summarizes the design and analysis of a lathe machine. It describes the materials selected for different parts of the lathe based on their properties like strength, rigidity, and economy. It then outlines the specifications of the lathe model created in Pro-E, including dimensions and maximum workpiece size. Cutting forces acting on the tool for a given depth of cut and feed rate are calculated. A static structural analysis of the lathe assembly is performed in ANSYS to determine stress distributions in parts like the tool, base, tail stock, and at interfaces. The analysis shows stresses and deformations are within allowable limits.
this is 2nd presentation of manufacturing processes in this presentation we discuss in detail about the theory of metal cutting, machiening processes,cutters etc
This document discusses tool geometry for single point cutting tools. It defines key tool angles like rake angle and clearance angle. It describes three common systems for describing tool geometry: the machine reference (ASA) system, orthogonal rake system (ORS), and normal rake system (NRS). The ASA system uses the machine axes as reference, while ORS and NRS use tool-based reference planes and axes. ORS differs from NRS in that NRS accounts for cutting edge inclination through the normal plane, providing a more accurate description of tool geometry. Tool geometry is specified through values of angles and nose radius in the respective systems.
The document discusses theories of metal machining and chip formation. It describes how early theories like the theory of tear and theory of compression were later disproven. The generally accepted theory today is the theory of shear, which proposes that metal cutting occurs through shear along a plane at an angle to the cutting direction. The document also outlines the difficulties in studying metal cutting processes and how orthogonal cutting experiments were developed to simplify the analysis.
The document provides an overview of machining technology. It discusses the theory of chip formation in metal machining, including the forces involved and the Merchant equation. It also covers power and energy relationships as well as cutting temperatures in machining processes. The key machining operations of turning, drilling, and milling are explained along with tooling and parameters like cutting speed, feed rate, and depth of cut.
The document provides information about tool wear and tool life in machining processes. It discusses how tool wear occurs due to forces, temperature, and sliding action during cutting. The three main types of tool wear are flank wear, crater wear, and chipping. Flank wear is caused by abrasion from hard particles in the workpiece while crater wear results from high temperatures and diffusion at the tool-chip interface. Maintaining optimal cutting conditions and tool geometry can increase tool life. The document also covers tool materials, machinability factors, cutting fluids, machining forces, and lathe operations such as turning, facing, and threading.
To introduce machining process
To understand mechanics of chip formation
To study important parameters of metal machining
To understand methods of machining
This document discusses various topics related to machining processes and metal cutting. It begins with an outline of the module and then discusses why machining is important, providing accuracy and flexibility in machining various materials. It also notes some disadvantages of machining like waste of material and being time consuming. It then categorizes various material removal processes and provides theories and elements of metal cutting like chip formation and tool geometries. Specific processes like turning, milling and drilling are examined in further detail.
This document provides an overview of fundamental machining processes including turning, milling, drilling, broaching, and shaping. It discusses key concepts such as chip formation, cutting forces, tool angles, friction at tool-chip interfaces, and sources of chatter vibration. Examples are provided to calculate speeds, feeds, cutting times, and metal removal rates for different machining setups and operations.
metal cutting,manufacturing processes,Production TechnologyProf.Mayur Modi
The document discusses principles of metal cutting, classification of metal cutting processes, types of chips formed, chip thickness, velocity relationships, forces acting on the chip during orthogonal cutting according to Merchant's analysis, tool force dynamometers, cutting tool materials, tool coatings, and types of tool wear like crater wear. It provides information on the mechanics and physics involved in different metal cutting processes.
This document provides information on metal cutting processes and machining technology. It discusses:
- The purpose, principles, and definition of machining as a process to produce parts to desired dimensions and surface finish through chip removal.
- Classification of metal cutting processes as orthogonal or oblique cutting. It also discusses cutting tool angles like back rake angle and relief angles.
- Factors that affect cutting forces like rake angle, feed rate, and depth of cut.
- Tool designation systems like ASA and common tool materials like high-speed steel and cemented carbide.
- The mechanism of chip formation and different chip types like continuous, discontinuous, and chips with built-up edge
This presentation contains various aspects of metal cutting like mechanics of chip formation, single point cutting tool, chip breakers, types of chips,etc
The document describes Merchant's Force Circle method for calculating forces in metal cutting. It involves drawing vectors representing cutting force, thrust force, resultant force, friction force, normal force, and shear force on a circle. The positions of the vectors' heads and tails on the circle allow calculation of these forces and their angles. The method can be used to determine power requirements and optimize cutting conditions like rake angle to minimize forces and temperature.
The document discusses research on integrating geometric and mechanistic models for cutting process simulation and feedrate optimization in five-axis milling of free-form surfaces. It presents a method for extracting cutter-workpiece engagement geometry from CAD/CAM toolpaths to be used as input for a discrete mechanistic force prediction model. Experimental validation showed good agreement between simulated and measured cutting forces. The integrated modeling approach uses geometric simulation to dynamically update the workpiece model and determine cutter contact areas, while the mechanistic model estimates forces to calculate optimal feedrates within constraints of part quality, tool life, and machine limitations.
Cutting power & Energy Consideration in metal cuttingDushyant Kalchuri
Cutting power is an important parameter, especially in the case of rough operations, as it makes it possible to:
select and invest in a machine with a power output suited to the operation being carried out
obtain the cutting conditions that allow the machine's power to be used in the most effective way possible, so as to ensure optimal material removal rate while taking into account the capacity of the tool being used.
This document discusses tool geometry and signatures for single point cutting tools. It defines key tool angles such as rake angles, clearance angles, and cutting edge angles. Rake angles are provided for chip flow, while clearance angles avoid rubbing between the tool and workpiece. The document then explains ANSI tool signature standards and defines each element of a signature for a single point tool, including back rake angle, side rake angle, end and side relief angles, end and side cutting edge angles, and nose radius. An example signature of 0-7-6-8-15-16-0.8 is provided.
The document discusses cutting tool materials and Merchant's Circle Diagram (MCD) for calculating forces in machining. It provides information on 7 common cutting tool materials: high carbon steel, high speed steel, cast alloys, cemented carbides, coated carbides, ceramics, and diamonds. It also explains what MCD is and how it can be used graphically to calculate cutting, tangential, friction, normal, shear and normal shear forces from measured cutting forces. An example calculation using MCD is provided.
The document discusses machining processes and cutting tools. It provides definitions of machining and cutting tools. It describes:
- The importance of machining processes in manufacturing precise parts.
- Objectives of machining like high material removal rate and surface finish, low tool and power costs.
- Classification of cutting tools based on how relative motion is provided between tool and workpiece.
- Key terms related to cutting tool geometry like rake angle, relief angle, and their influence on tool strength and chip removal.
- Mechanism of chip formation and different types of chips produced.
Machining is any process in which a cutting tool is used to remove small chips of material from the workpiece (the workpiece is often called the "work"). To perform the operation, relative motion is required between the tool and the work.
signature of single point cutting toolVaibhav Kadu
This document discusses tool signatures and different tool geometry systems. It provides information on:
1) The objective is to explain tool signatures, how tool angles affect machining, and why understanding signatures is important.
2) Tool signatures specify the key angles of a cutting tool in a standardized way. They indicate the active angles during cutting.
3) Three common tool geometry systems are described - ASA, ORS, and NRS. They each define tool angles differently based on different reference planes.
This document discusses mechanics of metal cutting. It covers topics like cutting models, forces, energies, and material removal rate. The orthogonal cutting model is described, which assumes a straight cutting edge generating a plane surface. Key terms like rake angle, shear angle, and cutting forces are defined. The relationships between cutting parameters, forces, power, and specific cutting energy are explained using the orthogonal model. Limitations of this simplified model are also noted.
cutting forces(static) simulation on latheTaliya Hemanth
This document summarizes the design and analysis of a lathe machine. It describes the materials selected for different parts of the lathe based on their properties like strength, rigidity, and economy. It then outlines the specifications of the lathe model created in Pro-E, including dimensions and maximum workpiece size. Cutting forces acting on the tool for a given depth of cut and feed rate are calculated. A static structural analysis of the lathe assembly is performed in ANSYS to determine stress distributions in parts like the tool, base, tail stock, and at interfaces. The analysis shows stresses and deformations are within allowable limits.
this is 2nd presentation of manufacturing processes in this presentation we discuss in detail about the theory of metal cutting, machiening processes,cutters etc
This document discusses tool geometry for single point cutting tools. It defines key tool angles like rake angle and clearance angle. It describes three common systems for describing tool geometry: the machine reference (ASA) system, orthogonal rake system (ORS), and normal rake system (NRS). The ASA system uses the machine axes as reference, while ORS and NRS use tool-based reference planes and axes. ORS differs from NRS in that NRS accounts for cutting edge inclination through the normal plane, providing a more accurate description of tool geometry. Tool geometry is specified through values of angles and nose radius in the respective systems.
The document discusses theories of metal machining and chip formation. It describes how early theories like the theory of tear and theory of compression were later disproven. The generally accepted theory today is the theory of shear, which proposes that metal cutting occurs through shear along a plane at an angle to the cutting direction. The document also outlines the difficulties in studying metal cutting processes and how orthogonal cutting experiments were developed to simplify the analysis.
The document provides an overview of machining technology. It discusses the theory of chip formation in metal machining, including the forces involved and the Merchant equation. It also covers power and energy relationships as well as cutting temperatures in machining processes. The key machining operations of turning, drilling, and milling are explained along with tooling and parameters like cutting speed, feed rate, and depth of cut.
The document provides information about tool wear and tool life in machining processes. It discusses how tool wear occurs due to forces, temperature, and sliding action during cutting. The three main types of tool wear are flank wear, crater wear, and chipping. Flank wear is caused by abrasion from hard particles in the workpiece while crater wear results from high temperatures and diffusion at the tool-chip interface. Maintaining optimal cutting conditions and tool geometry can increase tool life. The document also covers tool materials, machinability factors, cutting fluids, machining forces, and lathe operations such as turning, facing, and threading.
To introduce machining process
To understand mechanics of chip formation
To study important parameters of metal machining
To understand methods of machining
This document discusses various topics related to machining processes and metal cutting. It begins with an outline of the module and then discusses why machining is important, providing accuracy and flexibility in machining various materials. It also notes some disadvantages of machining like waste of material and being time consuming. It then categorizes various material removal processes and provides theories and elements of metal cutting like chip formation and tool geometries. Specific processes like turning, milling and drilling are examined in further detail.
This document provides an overview of fundamental machining processes including turning, milling, drilling, broaching, and shaping. It discusses key concepts such as chip formation, cutting forces, tool angles, friction at tool-chip interfaces, and sources of chatter vibration. Examples are provided to calculate speeds, feeds, cutting times, and metal removal rates for different machining setups and operations.
metal cutting,manufacturing processes,Production TechnologyProf.Mayur Modi
The document discusses principles of metal cutting, classification of metal cutting processes, types of chips formed, chip thickness, velocity relationships, forces acting on the chip during orthogonal cutting according to Merchant's analysis, tool force dynamometers, cutting tool materials, tool coatings, and types of tool wear like crater wear. It provides information on the mechanics and physics involved in different metal cutting processes.
This document provides information on metal cutting processes and machining technology. It discusses:
- The purpose, principles, and definition of machining as a process to produce parts to desired dimensions and surface finish through chip removal.
- Classification of metal cutting processes as orthogonal or oblique cutting. It also discusses cutting tool angles like back rake angle and relief angles.
- Factors that affect cutting forces like rake angle, feed rate, and depth of cut.
- Tool designation systems like ASA and common tool materials like high-speed steel and cemented carbide.
- The mechanism of chip formation and different chip types like continuous, discontinuous, and chips with built-up edge
This presentation contains various aspects of metal cutting like mechanics of chip formation, single point cutting tool, chip breakers, types of chips,etc
The document describes Merchant's Force Circle method for calculating forces in metal cutting. It involves drawing vectors representing cutting force, thrust force, resultant force, friction force, normal force, and shear force on a circle. The positions of the vectors' heads and tails on the circle allow calculation of these forces and their angles. The method can be used to determine power requirements and optimize cutting conditions like rake angle to minimize forces and temperature.
The document discusses research on integrating geometric and mechanistic models for cutting process simulation and feedrate optimization in five-axis milling of free-form surfaces. It presents a method for extracting cutter-workpiece engagement geometry from CAD/CAM toolpaths to be used as input for a discrete mechanistic force prediction model. Experimental validation showed good agreement between simulated and measured cutting forces. The integrated modeling approach uses geometric simulation to dynamically update the workpiece model and determine cutter contact areas, while the mechanistic model estimates forces to calculate optimal feedrates within constraints of part quality, tool life, and machine limitations.
This document presents a theoretical method for estimating the machined surface profile in ball-nosed end milling without actual machining. The method derives fundamental simultaneous equations to identify the cusp height at any point on the workpiece based on the geometric relationship between the cutting edge movement and the normal line at that point. Numerical calculations using these equations can graphically estimate and illustrate the machined surface profile. Results show that maximum and minimum cusp heights exist within a narrow range of tool orientation less than 3 degrees near the normal direction.
The document discusses orthogonal cutting and how to calculate cutting forces. It describes orthogonal cutting as assuming the cutting edge is perpendicular to the direction of tool motion, allowing analysis in one plane. It can be achieved by turning a thin-walled tube with the cutting edge perpendicular to the tube axis. The document then discusses measuring cutting and tangential forces using a dynamometer and calculating velocities and forces using vector diagrams, including Merchant's force circle method.
Fe investigation of semi circular curved beam subjected to out-of-plane loadeSAT Journals
Abstract Curved beams are used as machine or structural members in many applications. Based on application of load they can be classified into two categories. Curved beams subjected to In-Plane loads are more familiar and are used for crane hooks, C-clamps etc. The other categories of curved beams are the ones that are subjected to out-of-plane loads. They find applications in automobile universal joints, raider arms and many civil structures etc.The results of this research on semicircular curved beam subjected to out-of-plane loads have revealed some interesting results. For semicircular curved beams subjected to out-of-plane loads, it is shown that every section is subjected to a combination of transverse shear force, bending moment and twisting moment. By using ANSYS tool it is shown that Maximum principal stress occurs at section 120 degrees from the section containing the loading line. Moreover it is observed that fixed end of this curved beam is subjected to a state of pure shear. Key Words: Semi circular curved beam, Stress in curved beam, Out-of-plane load, FE analysis.
IRJET- Static Analysis of Cutting Tool using Finite Element ApproachIRJET Journal
This document summarizes a study that used finite element analysis to examine the static stress on a single point cutting tool under different tool geometry parameters. A CAD model of the cutting tool and workpiece was created in ANSYS. The tool's total deformation and von Mises stress were calculated for variations in relief angle, back rake angle, and chip formation. The results showed that increasing the relief angle and back rake angle decreased tool stress levels significantly. A positive back rake angle helped move chips away from the workpiece and led to easier material shearing over compression. Continuous chip formation with a positive rake angle also helped maintain tool safety during hard material cutting. In conclusion, a positive rake angle is preferred for machining
This document discusses the theory and relationships involved in metal machining processes. It covers the basics of chip formation and cutting tool geometry, defines the key forces and stresses in machining, and derives the fundamental Merchant equation relating cutting forces and tool geometry. It also provides equations for calculating shear strain, shear stress, cutting power requirements, and the influence of tool geometry on forces and chip removal. Overall, the document establishes the theoretical foundations for understanding and analyzing metal cutting operations.
This document discusses mechanics of metal cutting. It covers tool terminology and geometry, orthogonal vs oblique cutting, turning forces, velocity diagrams, and Merchant's circle. The key forces in orthogonal cutting are cutting force, thrust force, shear force, and friction force. Velocity and force diagrams are used to calculate these forces based on cutting parameters like rake angle, shear angle, and friction angle. Cutting power, material removal rate, specific cutting energy, and stresses on the shear plane and tool rake face are also discussed. Experimental methods for measuring cutting forces and power are mentioned.
1. The document discusses different types of dynamometers used to measure cutting forces in machining processes like turning, drilling, and milling.
2. It describes the general principle of measurement which involves converting the physical variable like force into a signal using a transducer, conditioning the signal, and reading or recording the signal.
3. Common transducers discussed include strain gauges, which measure elastic deformation from forces, and piezoelectric transducers, which generate voltage proportional to applied pressure.
IRJET- The Effect of Tooth Thickness on Root Stress of Internal Spur Gear Mec...IRJET Journal
This document summarizes a study that analyzed the effect of tooth thickness on root stress in an internal spur gear mechanism using finite element analysis. The study found that by increasing the tooth thickness of the pinion gear and decreasing the thickness of the internal gear from the standard value of half the pitch, the maximum bending stresses in the two gears could be balanced. Specifically, a tooth thickness of 0.572 times the pitch for the pinion and 0.428 times the pitch for the internal gear resulted in approximately equal stresses of 47.3 MPa in both gears. This tooth thickness optimization also reduced the total weight of the gear mechanism.
To develop algorithm to create node at desired location on beam using absorberIRJET Journal
This document presents a study on developing an algorithm to reduce handle vibrations of a grass trimmer by imposing nodes at desired locations on the trimmer pipe using a variable stiffness vibration absorber. The grass trimmer is modeled as a free-free beam with lumped masses representing the engine, cutter head, and handle. An algorithm is developed based on the beam's equations of motion to iteratively find the absorber frequency required to impose a node and minimize vibration at the handle location. Numerical simulations and experimental tests are conducted to validate the effectiveness of the proposed method in suppressing vibrations at the handle by over 75%.
This document gives the class notes of Unit-8: Torsion of circular shafts and elastic stability of columns. Subject: Mechanics of materials.
Syllabus contest is as per VTU, Belagavi, India.
Notes Compiled By: Hareesha N Gowda, Assistant Professor, DSCE, Bengaluru-78.
The document discusses the mechanics of metal cutting. It covers topics such as cutting models, turning forces, power and energies, tool terminology, cutting geometry, material removal rate, orthogonal and oblique cutting models, turning and facing forces, velocities, cutting forces, the merchant's circle diagram, stresses, power, specific cutting energy, and violations of orthogonal cutting models. It provides the theoretical framework for understanding metal cutting and machining processes.
1. The document discusses the dynamics of machines and introduces the key concepts of kinematics, dynamics, kinetics, and statics as the four main branches of the theory of machines.
2. It then discusses static and dynamic force analysis and introduces concepts like inertia forces and torques. D'Alembert's principle is explained which states that inertia and external forces together result in static equilibrium.
3. Methods for dynamic analysis of reciprocating engines like graphical and analytical methods are introduced. Key forces on reciprocating parts like piston effort, connecting rod force, thrust, crank pin effort, and crank effort are defined.
The document discusses metal cutting mechanics. It covers tool terminology and geometry, orthogonal vs oblique cutting, turning forces, velocity diagrams, and Merchant's circle. The key forces in orthogonal cutting are cutting force, thrust force, shear force, and friction force. Velocity and force diagrams are used to calculate these forces based on tool geometry, cutting conditions, and material properties. The power required and specific energy of cutting can also be determined from the forces and velocities. Understanding cutting forces is important for machine tool design, process optimization, and tool condition monitoring.
Analysis of bending strength of bevel gear by FEMAM Publications
In bevel gear will have a tangential load, radial load and axial load due to the speed and torque .This will be a
transient phenomenon and will need careful stress analysis for determining life of the gear. In gear design, the Mechanism will
be more Challenging as it should transmit high torque. All gears are not to be used for such high torque applications due to their
low capacity and strength. Bevel gears are used in differential drives, which can transmit power to two axles spinning at different
speeds, such as those on a cornering automobile, hand drill, to redirect the shaft from the horizontal gas turbine engine to the
vertical rotor. In this paper a comparison between Lewis equation and Ansys workbench is done.
This document discusses machining processes and theories for predicting chip formation. It explains that machining involves selectively removing material with sharp tools, similar to plastic deformation. Lee-Shaffer's theory models the shear zone and uses geometry to predict the shear plane angle, but it does not always match experiments because it does not consider material properties or stresses. Measuring machining forces provides insights for process optimization, tool design, and more. Forces develop on the tool rake surface and shear plane during orthogonal cutting.
Classification of metal removal process and machines: Concept of generatrix and directrix Geometry of single point cutting tool and tool angles, tool nomenclature in ASA, ORS, NRS. Concept of orthogonal and oblique cutting, Mechanism of Chip Formation: Type of chips. Mechanics of metal cutting, interrelationships between cutting force, shear angle, strain and strain rate. Various theories of metal cutting, Thermal aspects of machining and measurement of chip tool interface temperature, Friction in metal cutting
Strength Analysis and Optimization Design about the key parts of the RobotIJRES Journal
Study on structure optimization design about Flip Arms of Mobile Robot. First conducted
preliminary structural design, and established finite element analysis model by HYPERMESH, use ANSYS
software to study Flip Arms Stress distribution and structure optimization. Strength check to ensure the strength
and stiffness of Flip Arms meet safety requirements, and make sure the reliability of the design, to provide a
theoretical basis for the structural optimization design of Flip Arms. Optimization design considering the
weighted compliance as the object function, the frame was improved by modifying the parameters which are
most sensitive to the character of the frame structure. The results showed that structural optimization design
without affecting the reliability of Flip Arms, reducing the quality of the parts improved and the Flip Arms
flexible mobility, to provide a theoretical basis for the structural design of robot.
This document discusses stakeholder management in project management. It covers identifying stakeholders, creating a stakeholder register, performing stakeholder analysis, developing a stakeholder management plan, managing stakeholder engagement, and controlling stakeholder engagement. The document emphasizes the importance of stakeholder management to project success.
Advanced manufacturing is the production of complex machines through the application of new technologies and processes. It involves utilizing enabling technologies and innovative design and business processes to create novel, high value and competitive products efficiently. Advanced manufacturing is relative to a country's existing capabilities and involves upgrading processes and technologies at any stage of production. Understanding how global value chains are managed can provide insights into how countries can integrate into global manufacturing industries.
The document summarizes the EFFRA Roadmap for Factories of the Future 2020. It outlines six research priority domains: 1) Advanced Manufacturing Processes 2) Adaptive and Smart Manufacturing Systems 3) Digital, Virtual and Resource-Efficient Factories 4) Collaborative and Mobile Enterprises 5) Human-Centric Manufacturing 6) Customer-Focused Manufacturing. The roadmap aims to address challenges in economic, social and environmental sustainability through focus on the right technologies for the identified opportunities and challenges.
1. An ERP system manages a company's resources like products, customers, suppliers, employees, facilities, finances, etc. It integrates data across departments for improved communication, productivity and efficiency.
2. Originally, departments used separate information systems like custom programs or spreadsheets. This led to data silos with inefficient exchange of information between departments.
3. The development of local area networks and client-server computing in the late 1980s/1990s allowed departments to connect their systems and exchange data seamlessly, addressing the data silo issue. This paved the way for integrated ERP systems spanning all company resources.
The document discusses the evolution and history of ERP systems from inventory control packages in the 1960s to extended ERP systems today. It describes how ERP systems evolved from materials requirements planning (MRP) systems in the 1970s to manufacturing resource planning (MRP II) systems in the 1980s to integrated enterprise resource planning (ERP) systems in the 1990s that began to incorporate additional modules. Today's extended ERP systems provide connections to functions like customer relationship management (CRM) and supply chain management (SCM). The document also outlines some of the benefits and challenges of implementing ERP systems for organizations.
This document provides information about a manufacturing processes laboratory course, including:
- The schedule lists 13 sessions over 14 weeks for demonstrations, exercises, an exam, and student projects.
- General instructions are provided on safety, submitting reports, dress code, cleaning work areas, and more.
- Recommended reading materials are listed to refer to for answering question bank questions.
- An introduction is given on the different parts of the course, including demonstrations, exercises, an exam, and student projects focused on casting, metal forming, and other manufacturing processes.
The document introduces data warehouses and discusses the differences between online transaction processing (OLTP) and online analytical processing (OLAP). It notes that a data warehouse is a subject-oriented, integrated collection of data that helps analysts make informed decisions. OLTP systems emphasize fast processing of short transactions, maintaining integrity, and throughput, while OLAP systems handle complex queries, aggregations, and response time.
Haiku Deck is a presentation tool that allows users to create Haiku style slideshows. The tool encourages users to get started making their own Haiku Deck presentations which can be shared on SlideShare. In just a few sentences, it pitches the idea of using Haiku Deck to easily create visual presentations.
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3. Instructional Objectives
At the end of this lesson, the student would be able to
(i) Ascertain the benefits and state the purposes of determining cutting
forces
(ii) Identify the cutting force components and conceive their
significance and role
(iii) Develop Merchant’s Circle Diagram and show the forces and their
relations
(iv) Illustrate advantageous use of Merchant’s Circle Diagram
(i) Benefit of knowing and purpose of determining cutting
forces.
The aspects of the cutting forces concerned :
• Magnitude of the cutting forces and their components
• Directions and locations of action of those forces
• Pattern of the forces : static and / or dynamic.
Knowing or determination of the cutting forces facilitate or are required for :
• Estimation of cutting power consumption, which also enables
selection of the power source(s) during design of the machine tools
• Structural design of the machine – fixture – tool system
• Evaluation of role of the various machining parameters ( process –
VC, so, t, tool – material and geometry, environment – cutting fluid)
on cutting forces
• Study of behaviour and machinability characterisation of the work
materials
• Condition monitoring of the cutting tools and machine tools.
(ii) Cutting force components and their significances
The single point cutting tools being used for turning, shaping, planing, slotting,
boring etc. are characterised by having only one cutting force during
machining. But that force is resolved into two or three components for ease of
analysis and exploitation. Fig. 8.1 visualises how the single cutting force in
turning is resolved into three components along the three orthogonal
directions; X, Y and Z.
The resolution of the force components in turning can be more conveniently
understood from their display in 2-D as shown in Fig. 8.2.
Version 2 ME IIT, Kharagpur
4. R
PX
PY
PZ
Fig. 8.1 Cutting force R resolved into PX, PY and PZ
PX
PY
PXY
PX'
PY'
PZ
PZ'
PXY
PXY'
Fig. 8.2 Turning force resolved into PZ, PX and PY
The resultant cutting force, R is resolved as,
Version 2 ME IIT, Kharagpur
5. XYZ PPR += (8.1)
and YXXY PPP += (8.2)
where, PX = PXYsinφ and PY = PXYcosφ (8.3)
where, PZ = tangential component taken in the direction of Zm axis
PX = axial component taken in the direction of longitudinal
feed or Xm axis
PY = radial or transverse component taken along Ym axis.
In Fig. 8.1 and Fig. 8.2 the force components are shown to be acting on the
tool. A similar set of forces also act on the job at the cutting point but in
opposite directions as indicated by PZ', PXY', PX' and PY' in Fig. 8.2
Significance of PZ, PX and PY
PZ : called the main or major component as it is the largest in magnitude.
It is also called power component as it being acting along and being
multiplied by VC decides cutting power (PZ.VC) consumption.
Py : may not be that large in magnitude but is responsible for causing
dimensional inaccuracy and vibration.
PX : It, even if larger than PY, is least harmful and hence least significant.
Cutting forces in drilling
In a drill there are two main cutting edges and a small chisel edge at the
centre as shown in Fig. 8.3.
The force components that develop (Fig. 8.3) during drilling operation are :
• a pair of tangential forces, PT1 and PT2 (equivalent to PZ in turning)
at the main cutting edges
• axial forces PX1 and PX2 acting in the same direction
• a pair of identical radial force components, PY1 and PY2
• one additional axial force, PXe at the chisel edge which also
removes material at the centre and under more stringent condition.
PT1 and PT2 produce the torque, T and causes power consumption PC as,
T = PT x ½ (D) (8.3)
and PC= 2πTN (8.4)
where, D = diameter of the drill
and N = speed of the drill in rpm.
The total axial force PXT which is normally very large in drilling, is provided by
PXT = PX1 + PX2 + PXe (8.5)
But there is no radial or transverse force as PY1 and PY2, being in opposite
direction, nullify each other if the tool geometry is perfectly symmetrical.
Version 2 ME IIT, Kharagpur
6. PX1
PY1
PX2
PY2
PXe
PT1
PT2
Fig. 8.3 Cutting forces in drilling.
Cutting forces in milling
The cutting forces (components) developed in milling with straight fluted slab
milling cutter under single tooth engagement are shown in Fig. 8.4.
The forces provided by a single tooth at its angular position, ψI are :
• Tangential force PTi (equivalent to PZ in turning)
• Radial or transverse force, PRi (equivalent to PXY in turning)
• R is the resultant of PT and PR
• R is again resolved into PZ and PY as indicated in Fig. 8.4 when Z
and Y are the major axes of the milling machine.
Those forces have the following significance:
o PT governs the torque, T on the cutter or the milling arbour as
T = PT x D/2 (8.5)
and also the power consumption, PC as
PC = 2πTN (8.6)
where, N = rpm of the cutter.
The other forces, PR, PZ, PY etc are useful for design of the
Machine – Fixture – Tool system.
In case of multitooth engagement;
Total torque will be D/2.∑PTi and total force in Z and Y direction
will be ∑PZ and ∑PY respectively.
One additional force i.e. axial force will also develop while milling by
helical fluted cutter
Version 2 ME IIT, Kharagpur
7. PT
PZ
PY
PR
ω
sm
R
Fig. 8.4 Cutting forces developed in plain milling
(with single tooth engagement)
(iii) Merchant’s Circle Diagram and its use
In orthogonal cutting when the chip flows along the orthogonal plane, πO, the
cutting force (resultant) and its components PZ and PXY remain in the
orthogonal plane. Fig. 8.5 is schematically showing the forces acting on a
piece of continuous chip coming out from the shear zone at a constant speed.
That chip is apparently in a state of equilibrium.
βo
γo
R
Pn
Ps
PZ
PXY
R1
F
N
Fig. 8.5 Development of Merchants Circle Diagram.
Version 2 ME IIT, Kharagpur
8. The forces in the chip segment are :
r force and
e shear force
o From job-side :
• PS – shea
• Pn – force normal to th
RPP ns =+ (resultant)where,
o From tool side :
RR =1 (in• state of equilibrium)
• where NFR +=1
• N = force normal to rake face
terface.
The result rther as
• F = friction force at chip tool in
ing cutting force R or R1 can be resolved fu
XYZ PPR +=1
where, PZ = force along the velocity vector
is called Merchant’s circle
The significance of the forces displayed in the Merchant’s Circle Diagram are :
and PXY = force along orthogonal plane.
The circle(s) drawn taking R or R1 as diameter
which contains all the force components concerned as intercepts. The two
circles with their forces are combined into one circle having all the forces
contained in that as shown by the diagram called Merchant’s Circle Diagram
(MCD) in Fig. 8.6
η
Fig. 8.6 Merchant’ s Circle Diagram with cutting forces.
PS – the shear force essentially required to produce or separate the
βo
γo
PXY
Pn PZ
R
F
N
Ps
Tool
Chip
work
Version 2 ME IIT, Kharagpur
9. chip from the parent body by shear
Pn – inherently exists along with PS
F – friction force at the chip tool interface
N – force acting normal to the rake surface
PZ – main force or power component acting in the direction of cutting
velocity
YX PP +PXY –
The magnitude of PS rovides the yield shear strength of the work material
the nature and degree of
iv) Advantageous use of Merchant’s Circle Diagram
roper use of MCD enables the followings :
te determination of several other
• strength can
• different forces are easily developed.
ome limitations of use of MCD
• Merchant’s Circle Diagram(MCD) is valid only for orthogonal cutting
• ed on single shear plane theory.
he advantages of constructing and using MCD has been illustrated as by an
straight turning under orthogonal cutting condition with
sinφ, where PX and φ are known.
value
• e.g. 100 N = 1 cm) for presenting PZ and
• d PXY along and normal to
p
under the cutting condition.
The values of F and the ratio of F and N indicate
interaction like friction at the chip-tool interface. The force components PX, PY,
PZ are generally obtained by direct measurement. Again PZ helps in
determining cutting power and specific energy requirement. The force
components are also required to design the cutting tool and the machine tool.
(
(MCD)
P
• Easy, quick and reasonably accura
forces from a few known forces involved in machining
Friction at chip-tool interface and dynamic yield shear
be easily determined
Equations relating the
S
• by the ratio, F/N, the MCD gives apparent (not actual) coefficient of
friction
It is bas
T
example as follows ;
Suppose, in a simple
given speed, feed, depth of cut and tool geometry, the only two force
components PZ and PX are known by experiment i.e., direct measurement,
then how can one determine the other relevant forces and machining
characteristics easily and quickly without going into much equations and
calculations but simply constructing a circle-diagram. This can be done by
taking the following sequential steps :
• Determine PXY from PX = PXY
• Draw the tool and the chip in orthogonal plane with the given
of γo as shown in Fig. 8.4
Choose a suitable scale (
PXY in cm
Draw PZ an CV as indicated in Fig. 8.6
• Draw the cutting force R as the resultant of PZ and PXY
• Draw the circle (Merchant’s circle) taking R as diameter
Version 2 ME IIT, Kharagpur
10. • Get F and N as intercepts in the circle by extending the tool rake
• the scale and get the values of F
• ermining Ps (and Pn) the value of the shear angle βo has to
surface and joining tips of F and R
Divide the intercepts of F and N by
and N
For det
be evaluated from
o
o
o
γζ
γ
β
cos
tan =
sin−
where γ is known and ζ has to be obtained fromo
1a
1 o
so and φ are known and a2 is either known, if not, it has to be
• o and then Ps and Pn as
• y dividing their corresponding lengths
• of apparent coefficient of friction, μa at the chip tool
2a
=ζ where a = s sinφ
measured by micrometer or slide calliper
Draw the shear plane with the value of β
intercepts shown in Fig. 8.6.
Get the values of Ps and Pn b
by the scale
Get the value
interface simply from the ratio,
N
F
=μ
Get the friction angle, η, if desired, either from tan
a
• η= μa or directly
•
from the MCD drawn as indicated in Fig. 8.6.
Determine dynamic yield shear strength (τs) of the work material
under the cutting condition using the simple expression
s
sP
=τs
A
where, As = shear area as indicated in Fig. 8.7
o
otsba 11
==
o ββ sinsin
t = depth of cut (known)
Fig. 8.7 Shear area in orthogonal turning
Shear area
Version 2 ME IIT, Kharagpur
11. Evaluation of cutting power consumption and specific energy requirement
ied to be reduced but without sacrificing MRR.
(8.4)
cially Vf are very small, PX.Vf can be neglected and
of material, is an important machinability characteristics
terials and grinding requires very large amount of specific energy
Cutting power consumption is a quite important issue and it should always be
tr
Cutting power consumption, PC can be determined from,
PC = PZ.VC + PX.Vf
where, Vf = feed velocity
= Nso/1000 m/min [N=rpm]
Since both PX and Vf, spe
then PC ≅ PZ.VC
Specific energy requirement, which means amount of energy required to
remove unit volume
of the work material. Specific energy requirement, Us, which should be tried to
be reduced as far as possible, depends not only on the work material but also
the process of the machining, such as turning, drilling, grinding etc. and the
machining condition, i.e., VC, so, tool material and geometry and cutting fluid
application.
Compared to turning, drilling requires higher specific energy for the same
work-tool ma
for adverse cutting edge geometry (large negative rake).
Specific energy, Us is determined from
o
ZCZ
s
tsMRR
U ==
PVP .
Exercise - 8
Solution of some Problems
Problem 1
γo = 10o, it was found PZ= 1000 N,
ζ
During turning a ductile alloy by a tool of
P = 400 N,X PY= 300 N and = 2.5. Evaluate, using MCD, the values of F, N
and μ as well as Ps and Pn for the above machining.
Solution :
1 cm
Version 2 ME IIT, Kharagpur
12. • force, 22
YXXY PPP += = 22
)300()400( + = 500 N
•
e tool tip with γ o
and PXY=500/200=2.5cm
•
and N as shown
10o) = 0.42
0 = 600 N; N = 4.6x200 = 920 N;
roblem 2
uring turning a steel rod of diameter 160 mm at speed 560 rpm, feed 0.32
depth of cut 4.0 mm by a ceramic insert of geometry
. Determine with the help of
, m , P , P , cutting power and specific
• PXY=PX/sinφ = 800/sin75o = 828 N
e
s own
- sin γo)
2/a1 = a2/(sosinφ) = 3.2
-10o))}= 16.27o
Select a scale: 1 cm=200N
• Draw th =1o 0
• In scale, PZ=1000/200= 5 cm
• Draw PZ and PXY in the diagram
Draw R and then the MCD
• Extend the rake surface and have F
• Determine shear angle, βo
tan β = cosγ / (ζ - sinγo o
= cos10o/(2.5 – sin
o)
βo
• Draw Ps and P in the MCD
= tan-1(0.42) = 23o
n
• From the MCD, find F = 3x20
μ = F/N = 600/920 = 0.67
Ps = 3.4x200 = 680; Pn= 4.3x200 = 860 N
P
D
mm/rev. and
0o, —10o, 6o, 6o, 15o, 75o, 0 (mm)
The followings were observed :
PZ =1600 N, PX=800 N and chip thickness=1mm
MCD the possible values of F, N a s n
energy consumption.
Solution
• Sel ct a scale: 1cm = 400N
• Draw the tool tip with γ = -10oo
• Draw PZ and PXY in scale a sh
• Draw resultant and MCD
shear angle, βo
tan βo = cosγo / (ζ
where, ζ = a
β n-1(c oo = ta os(-10 ))/{(3.2 - sin(
Version 2 ME IIT, Kharagpur
13. • Draw Ps and Pn as shown
• Using the scale and intercepts determine
F = 1.75xscale = 700 N
N = 4.40xscale = 1760 N
μa = F/N = 700/1760 = 0.43
Ps = 3.0 x scale = 1200 N
Pn = 3.3 x scale = 1320 N
• Cutting Power, PC PC= PZ.VC where
Vc = πDN/1000 = π x160x560/1000 = 281.5 m/min
So, PC = 8 KW.
• Specific energy = PZ/(tso) = 1600/(4 x 0.32)= 1250 N-mm/mm3
Problem 3
For turning a given steel rod by a tool of given geometry if shear force PS ,
frictional force F and shear angle γo could be estimated to be 400N and 300N
respectively, then what would be the possible values of Px PY and PZ?
[use MCD]
Solution:
• tool geometry is known. Let rake angle be γo and principal cutting
edge angle be φ.
• Draw the tool tip with the given value of γo as shown.
• Draw shear plane using the essential value of βo
• using a scale (let 1cm=400N) draw shear force PS and friction force
F in the respective directions.
• Draw normals on PS and F at their tips as shown and let the
normals meet at a point.
• Join that meeting point with tool tip to get the resultant force
Version 2 ME IIT, Kharagpur
14. • Based on resultant force R draw the MCD and get intercepts for PZ
and Pxy
• Determine PZ and Pxy from the MCD
• PZ= __ x scale = ____ • Pxy = __ x scale = ___
• PY= PXY cosφ • PX= PXY sinφ
Problem - 4
During shaping like single point machining/turning) a steel plate at feed, 0.20
mm/stroke and depth 4 mm by a tool of λ = γ = 0o and φ = 90o PZ and PX
were found (measured by dynamometer) to be 800 N and 400 N respectively,
chip thickness, a2 is 0.4 mm. From the aforesaid conditions and using
Merchant’s Circle Diagram determine the yield shear strength of the work
material in the machining condition?
Solution
• It is orthogonal (λ= 0o) cutting MCD is valid
• draw tool with γo = 0o as shown
• PXY= PX/sinφ = 400/sin90o = 400 N
• Select a scale : 1 cm= 200N
• Draw PZ and PXY using that scale
PZ = 800/200 = 4 cm,
PXY = 400/200 = 2 cm
• Get R and draw the MCD
• Determine shear angle, βo from
tanβo = cosγo/(ζ — sinγo), γo= 0o and
ζ = a2/a1 a1 = (sosinφ) = 0.2 x sin90o = 0.2
βo = tan-1(0.2/0.4) = 26o
• Draw Ps along the shear plane and find Ps= 2.5 x 200 = 500 N
• Now, τs = Ps/As ;
Version 2 ME IIT, Kharagpur
15. As = (tso)/sinβo = 4 x 0.2/sin260 = 1.82 mm2
or, τs = 500/1.82
= 274.7 N/mm2
Version 2 ME IIT, Kharagpur