AE-681 Composite Materials is a 4 credit course taught by Dr. PM Mohite. The course covers topics such as introduction to unidirectional composites, analysis of lamina using classical laminate theory, design considerations, micromechanics, and performance under adverse environments. Reference materials include textbooks on composite materials and research papers. The grading policy includes assignments, midterm exams, and a final exam. Attendance will be monitored and late or copied assignments will be penalized.
Unit - I _ Composite Materials (A).pptxNinad Patil
Unit 1 of the document provides an introduction to composite materials. It defines composites as materials made of two or more chemically different constituents combined macroscopically. Examples of natural composites include wood, bone, and granite. Man-made composites include concrete, plywood, fiberglass, and cermets. Composites provide advantages like strength, stiffness, corrosion resistance, and aesthetics. They are used in various industries such as automotive, aerospace, sports, transportation, and infrastructure. Composites are classified as particulate or fibrous, depending on the reinforcement material, and can have random or preferred orientation of constituents.
207682663-Composite-Material-An-Introduction.pptxAbinash Behera
The document provides an introduction to composite materials, including:
1. A brief history of composite materials from natural occurrences to modern developments.
2. A definition of composite materials as a combination of two materials and a basic composition of a composite including a matrix and reinforcements.
3. A classification of composites based on the matrix phase (polymer, metal, ceramic) and the type of reinforcements used (fibers, particulates, flakes, whiskers).
4. An overview of how to characterize the mechanical properties of composites including rule of mixtures, loading orientation, and methods to estimate properties like modulus of elasticity, strength, and thermal expansion.
This document provides an introduction to composite materials, including:
- A composite consists of two or more materials combined to take advantage of their combined properties. Composites have higher strength and stiffness than metals but allow for tailored design.
- Common fibers include glass, carbon, and aramid, and matrices include polymers, metals, and ceramics. Different manufacturing methods are used to produce composites.
- Composites have advantages over metals like higher strength-to-weight and stiffness-to-weight ratios, corrosion resistance, and fatigue life. Their properties can be optimized for different applications.
The document discusses composite materials and fibers, including how to calculate strength and modulus for different fiber lengths and orientations. It covers long, short, and very short fibers. It also discusses various polymer matrix composites (PMCs) like glass fiber reinforced polymer (GFRP), carbon fiber reinforced polymer (CFRP), and aramid fiber reinforced polymer (AFRP), as well as fabrication methods like prepreg, pultrusion, and filament winding. Other topics include strengthening mechanisms, ceramic matrix composites, transformation toughening, and structural composites.
This document provides an overview of composite materials, including their advantages over traditional materials like metals. It discusses key topics such as the constituents of composites, different manufacturing methods, mechanical properties, applications, and challenges. The goal of the course is for students to gain an understanding of composite terminology, develop models to predict mechanical response, and be able to optimally design composite structures.
Dref iii polyester-wool blended friction-spun yarnNiloy Rahman
This document summarizes a journal article on the influence of sheath structure on twist and diameter of polyester-wool blended friction-spun yarn. The sheath composition and structure were varied by changing the core content and positioning polyester and wool fibers in different sheath layers. Yarn twist and diameter were observed under different drum and delivery speeds and core-sheath ratios. Twist was highest for a sheath structure with polyester on the inside and outside layers, and lowest for an all-wool sheath. Yarn diameter also varied depending on sheath composition and structure.
Dr. ABIRAJ K R discusses the evolution of archwires over the last century. Material science advancements have led to new archwire materials with improved properties beyond stainless steel and gold alloys. Key developments include nickel-titanium, beta titanium, and newer thermally-activated alloys that deliver non-linear force through stress-induced structural changes. Proper understanding of an archwire's material properties is important for effective force delivery in orthodontic treatment.
What is a Fiber?
Why are Fibres are used?
What is Fiber Reinforced Concrete (FRC)?
Steel fibers
Glass Fibers
Carbon Fiber
Cellulose Fiber
Polypropylene Fibers
Synthetic fibers
NATURAL FIBERS
Factors affecting the Properties of FRC
CLASSIFICATION OF POLYMERS.
Unit - I _ Composite Materials (A).pptxNinad Patil
Unit 1 of the document provides an introduction to composite materials. It defines composites as materials made of two or more chemically different constituents combined macroscopically. Examples of natural composites include wood, bone, and granite. Man-made composites include concrete, plywood, fiberglass, and cermets. Composites provide advantages like strength, stiffness, corrosion resistance, and aesthetics. They are used in various industries such as automotive, aerospace, sports, transportation, and infrastructure. Composites are classified as particulate or fibrous, depending on the reinforcement material, and can have random or preferred orientation of constituents.
207682663-Composite-Material-An-Introduction.pptxAbinash Behera
The document provides an introduction to composite materials, including:
1. A brief history of composite materials from natural occurrences to modern developments.
2. A definition of composite materials as a combination of two materials and a basic composition of a composite including a matrix and reinforcements.
3. A classification of composites based on the matrix phase (polymer, metal, ceramic) and the type of reinforcements used (fibers, particulates, flakes, whiskers).
4. An overview of how to characterize the mechanical properties of composites including rule of mixtures, loading orientation, and methods to estimate properties like modulus of elasticity, strength, and thermal expansion.
This document provides an introduction to composite materials, including:
- A composite consists of two or more materials combined to take advantage of their combined properties. Composites have higher strength and stiffness than metals but allow for tailored design.
- Common fibers include glass, carbon, and aramid, and matrices include polymers, metals, and ceramics. Different manufacturing methods are used to produce composites.
- Composites have advantages over metals like higher strength-to-weight and stiffness-to-weight ratios, corrosion resistance, and fatigue life. Their properties can be optimized for different applications.
The document discusses composite materials and fibers, including how to calculate strength and modulus for different fiber lengths and orientations. It covers long, short, and very short fibers. It also discusses various polymer matrix composites (PMCs) like glass fiber reinforced polymer (GFRP), carbon fiber reinforced polymer (CFRP), and aramid fiber reinforced polymer (AFRP), as well as fabrication methods like prepreg, pultrusion, and filament winding. Other topics include strengthening mechanisms, ceramic matrix composites, transformation toughening, and structural composites.
This document provides an overview of composite materials, including their advantages over traditional materials like metals. It discusses key topics such as the constituents of composites, different manufacturing methods, mechanical properties, applications, and challenges. The goal of the course is for students to gain an understanding of composite terminology, develop models to predict mechanical response, and be able to optimally design composite structures.
Dref iii polyester-wool blended friction-spun yarnNiloy Rahman
This document summarizes a journal article on the influence of sheath structure on twist and diameter of polyester-wool blended friction-spun yarn. The sheath composition and structure were varied by changing the core content and positioning polyester and wool fibers in different sheath layers. Yarn twist and diameter were observed under different drum and delivery speeds and core-sheath ratios. Twist was highest for a sheath structure with polyester on the inside and outside layers, and lowest for an all-wool sheath. Yarn diameter also varied depending on sheath composition and structure.
Dr. ABIRAJ K R discusses the evolution of archwires over the last century. Material science advancements have led to new archwire materials with improved properties beyond stainless steel and gold alloys. Key developments include nickel-titanium, beta titanium, and newer thermally-activated alloys that deliver non-linear force through stress-induced structural changes. Proper understanding of an archwire's material properties is important for effective force delivery in orthodontic treatment.
What is a Fiber?
Why are Fibres are used?
What is Fiber Reinforced Concrete (FRC)?
Steel fibers
Glass Fibers
Carbon Fiber
Cellulose Fiber
Polypropylene Fibers
Synthetic fibers
NATURAL FIBERS
Factors affecting the Properties of FRC
CLASSIFICATION OF POLYMERS.
Composites are materials made from two or more constituent materials with different physical or chemical properties. The materials remain separate within the finished structure to produce properties that are superior to those of the individual components. Composites consist of a reinforcement material, such as fibers, sheets or particles, embedded within a matrix material that maintains the relative positions of the reinforcements and allows for load transfer from the matrix to the reinforcement. Common reinforcement materials include glass, carbon and organic fibers while matrix materials include polymers, metals and ceramics. Composites offer advantages over traditional materials like high strength, light weight, design flexibility and resistance to corrosion.
The matrix in a composite is the continuous phase that transfers stress to the dispersed phase. Common matrix materials include metals, ceramics, and polymers. There are two possible strengthening mechanisms for particle reinforced composites: load transfer from the matrix to the particles and restriction of dislocation movement. The Young's modulus of a large particle composite can be calculated using upper and lower bounds. The critical length (Lc) of a fiber depends on factors like fiber diameter and matrix-fiber bond strength. Fibers of different lengths experience different stress distributions relative to the critical fiber length.
Composites consist of a combination of two or more materials, with a matrix and fiber reinforcement. The matrix holds the fibers together and typically transfers stress between fibers. Common matrix materials include polymers and metals. Fibers provide strength and stiffness and can be made of materials like glass, carbon, and Kevlar. Composites offer advantages over traditional materials like high strength to weight ratio, corrosion resistance, and anisotropic properties that allow for tailored designs. However, they also have disadvantages like higher costs and more complex manufacturing compared to metals.
The document discusses composite materials and their advantages over traditional materials. It defines a composite material as composed of two or more distinct materials or phases at the microscopic scale. Composites are needed to satisfy various application-specific requirements that no single material can fulfill. Reinforcements in composites come in fiber, particulate, flake, and whisker forms. Fibers are the most common and provide high strength when thin to minimize flaws and maximize fiber-matrix surface area for load transfer. The matrix holds the fibers in position and distributes loads between them. Composites allow designing materials with tailored and improved properties.
Introduction to composite_materials in aerospace_applicationsR.K. JAIN
Composite materials are widely used in aerospace applications due to their high strength to weight ratio, creep resistance, and strength retention at high temperatures. They are used in aircraft structures like wings, fuselages, and engine nacelles. Common composite materials include carbon fiber reinforced epoxy, glass reinforced epoxy, and aramid fiber reinforced epoxy. Composites offer advantages like weight savings, damage tolerance, and resistance to corrosion compared to metals. While composites will continue growing in aerospace due to their properties, higher costs remain a barrier to more widespread adoption.
This document provides an overview of composite materials, including their definition, constituents, terminology, classification, characteristics, and applications. Key points include:
- Composite materials are composed of a reinforcement phase (e.g. fibers) within a binder phase (e.g. matrix). They offer advantages like high strength and stiffness with low weight.
- Constituents include fibers, matrix, fillers, and coupling agents. Fiber materials include glass, carbon, and Kevlar. Matrix materials include metal, polymer, and ceramic.
- Composites find applications in aerospace, automotive, marine, sports, infrastructure, and medical due to their tailorable properties and corrosion resistance.
Review on Hybrid Composite Materials and its ApplicationsIRJET Journal
This document summarizes hybrid composite materials and their applications. It begins by defining composite materials as mixtures of two or more distinct materials that result in properties different from the individual components. Advanced composites consist of stiff fibers embedded in a matrix, such as carbon fibers in epoxy.
The document then discusses several types of composites - particle-reinforced, nanocomposites, fiber-reinforced, and graphene-based. It provides examples of each type and describes their reinforcement mechanisms. Applications are highlighted for aerospace, automotive, wind turbines, construction and more. The document concludes that studies of composite materials and technologies help research in this area.
The attached narrated power point presentation attempts to trace the necessity for cabling of optical fibers, reasons for different kinds of losses that occur in optical fibers, methods for mitigation of losses and a few examples of practical optical fiber cable structures. The material will be useful for KTU final year B Tech students who prepare for the subject EC 405, Optical Communications.
The documents discuss composite materials, which are combinations of two or more materials that have improved properties over the individual components. Composite materials consist of a reinforcement and a matrix. Reinforcements provide strength and stiffness, while the matrix binds the reinforcements together and protects them. Common reinforcement materials include fibers of glass, carbon, and aramid. Matrix materials include polymers, metals, and ceramics. The documents describe different types of composites based on the matrix, such as polymer matrix composites, metal matrix composites, and ceramic matrix composites. Manufacturing methods for polymer matrix composites like hand lay-up, filament winding, and pultrusion are also summarized.
This document discusses personal armor and ballistic protective materials. It summarizes that personal armor provides protection from energy impacts through absorbing, redistributing, or stopping energy. It then categorizes the main types of ballistic protective materials as hard body armor, which deflects projectiles, and soft body armor, which is preferred for its flexibility and comfort. The document concludes by discussing various fiber materials, weaves, and finishes used for optimal ballistic protection in personal armor.
orthodontic wires
types of wires
classification of wires
properties of wires
arch form
stainless steel wires and types
classification of stainless steel wires
This document provides information on carbon fiber reinforced polymer (CFRP) composites. It discusses the production of CFRP through various molding techniques like vacuum bagging and compression molding. It also covers the properties of CFRP composites like their light weight and high strength compared to other materials. Some disadvantages of CFRP like their high cost are also mentioned. Applications of CFRP composites in the aerospace, automotive and defense industries are summarized.
This document provides an overview of the general properties of orthodontic wire. It discusses the atomic arrangements of metallic materials used in orthodontics including face centered cubic, body centered cubic, and hexagonal close-packed structures. It also covers mechanical properties such as stress, strain, modulus of elasticity, stiffness, resilience and formability. Additional topics include work hardening, heat treatment, commonly used wire materials like stainless steel, nickel-titanium, and beta titanium alloys.
The document analyzes the performance of different prototype mooring hawsers manufactured with various constituent materials. Four prototypes were tested: 100% polyamide, 100% polyester, a hybrid of polyamide core and polyester jacket, and another hybrid with a different polyester. Dimensional properties and breaking strengths were measured, with all prototypes meeting international standards. The hybrid ropes performed better than 100% polyamide or polyester ropes, potentially offering longer service life.
TE-3113-7.pdf mechanics of fibrous Structure slidesNTU Faisalabad
This document provides an overview of mechanics of fibrous structures, specifically focusing on yarn structure. It discusses key aspects of yarn structure including fiber compactness, fiber arrangement, and fiber mobility. Fiber compactness influences yarn properties like strength and hand feel. Fiber arrangement impacts properties like strength and dimensional stability. Fiber mobility within yarns influences pilling resistance and other performance characteristics. The document also discusses different yarn types and theoretical models for predicting yarn tensile strength based on fiber and filament properties.
Unit 1-Introduction to Composites.pptxrohanpanage1
Composite materials can be summarized as follows:
1. Composite materials consist of a matrix and reinforcement, where the reinforcement is embedded within the matrix to improve its properties. Composites take advantage of the strengths of both materials.
2. Composites are classified based on their matrix, which can be polymer, metal, or ceramic. They are also classified based on the type of reinforcement, which can be particles, fibers, whiskers, or structural.
3. The matrix holds the reinforcement in place and protects it, while the reinforcement improves properties like strength and stiffness. Together they provide benefits like weight reduction, durability, and design flexibility compared to traditional materials.
This document discusses different types of natural fibers that can be used to make composites, including plant fibers like jute, banana, and stem fibers; animal fibers like wool and silk; and mineral fibers like asbestos. It provides details on the properties and processing of select natural fibers like jute, banana, and wool fibers. The applications and advantages of natural fiber composites are also mentioned.
UIET KUK MED Time table Jan to May 2024.pdfupender3
The document contains a timetable for the Mechanical Engineering Department of UIET. It lists the time slots and lecture numbers for different courses on various days of the week. It also lists the faculty members teaching different courses and time slots allocated for labs. The timetable is divided into sections for undergraduate courses on top and postgraduate/research courses at the bottom. It provides a comprehensive overview of class and lab schedules for all courses in the department.
Composites are materials made from two or more constituent materials with different physical or chemical properties. The materials remain separate within the finished structure to produce properties that are superior to those of the individual components. Composites consist of a reinforcement material, such as fibers, sheets or particles, embedded within a matrix material that maintains the relative positions of the reinforcements and allows for load transfer from the matrix to the reinforcement. Common reinforcement materials include glass, carbon and organic fibers while matrix materials include polymers, metals and ceramics. Composites offer advantages over traditional materials like high strength, light weight, design flexibility and resistance to corrosion.
The matrix in a composite is the continuous phase that transfers stress to the dispersed phase. Common matrix materials include metals, ceramics, and polymers. There are two possible strengthening mechanisms for particle reinforced composites: load transfer from the matrix to the particles and restriction of dislocation movement. The Young's modulus of a large particle composite can be calculated using upper and lower bounds. The critical length (Lc) of a fiber depends on factors like fiber diameter and matrix-fiber bond strength. Fibers of different lengths experience different stress distributions relative to the critical fiber length.
Composites consist of a combination of two or more materials, with a matrix and fiber reinforcement. The matrix holds the fibers together and typically transfers stress between fibers. Common matrix materials include polymers and metals. Fibers provide strength and stiffness and can be made of materials like glass, carbon, and Kevlar. Composites offer advantages over traditional materials like high strength to weight ratio, corrosion resistance, and anisotropic properties that allow for tailored designs. However, they also have disadvantages like higher costs and more complex manufacturing compared to metals.
The document discusses composite materials and their advantages over traditional materials. It defines a composite material as composed of two or more distinct materials or phases at the microscopic scale. Composites are needed to satisfy various application-specific requirements that no single material can fulfill. Reinforcements in composites come in fiber, particulate, flake, and whisker forms. Fibers are the most common and provide high strength when thin to minimize flaws and maximize fiber-matrix surface area for load transfer. The matrix holds the fibers in position and distributes loads between them. Composites allow designing materials with tailored and improved properties.
Introduction to composite_materials in aerospace_applicationsR.K. JAIN
Composite materials are widely used in aerospace applications due to their high strength to weight ratio, creep resistance, and strength retention at high temperatures. They are used in aircraft structures like wings, fuselages, and engine nacelles. Common composite materials include carbon fiber reinforced epoxy, glass reinforced epoxy, and aramid fiber reinforced epoxy. Composites offer advantages like weight savings, damage tolerance, and resistance to corrosion compared to metals. While composites will continue growing in aerospace due to their properties, higher costs remain a barrier to more widespread adoption.
This document provides an overview of composite materials, including their definition, constituents, terminology, classification, characteristics, and applications. Key points include:
- Composite materials are composed of a reinforcement phase (e.g. fibers) within a binder phase (e.g. matrix). They offer advantages like high strength and stiffness with low weight.
- Constituents include fibers, matrix, fillers, and coupling agents. Fiber materials include glass, carbon, and Kevlar. Matrix materials include metal, polymer, and ceramic.
- Composites find applications in aerospace, automotive, marine, sports, infrastructure, and medical due to their tailorable properties and corrosion resistance.
Review on Hybrid Composite Materials and its ApplicationsIRJET Journal
This document summarizes hybrid composite materials and their applications. It begins by defining composite materials as mixtures of two or more distinct materials that result in properties different from the individual components. Advanced composites consist of stiff fibers embedded in a matrix, such as carbon fibers in epoxy.
The document then discusses several types of composites - particle-reinforced, nanocomposites, fiber-reinforced, and graphene-based. It provides examples of each type and describes their reinforcement mechanisms. Applications are highlighted for aerospace, automotive, wind turbines, construction and more. The document concludes that studies of composite materials and technologies help research in this area.
The attached narrated power point presentation attempts to trace the necessity for cabling of optical fibers, reasons for different kinds of losses that occur in optical fibers, methods for mitigation of losses and a few examples of practical optical fiber cable structures. The material will be useful for KTU final year B Tech students who prepare for the subject EC 405, Optical Communications.
The documents discuss composite materials, which are combinations of two or more materials that have improved properties over the individual components. Composite materials consist of a reinforcement and a matrix. Reinforcements provide strength and stiffness, while the matrix binds the reinforcements together and protects them. Common reinforcement materials include fibers of glass, carbon, and aramid. Matrix materials include polymers, metals, and ceramics. The documents describe different types of composites based on the matrix, such as polymer matrix composites, metal matrix composites, and ceramic matrix composites. Manufacturing methods for polymer matrix composites like hand lay-up, filament winding, and pultrusion are also summarized.
This document discusses personal armor and ballistic protective materials. It summarizes that personal armor provides protection from energy impacts through absorbing, redistributing, or stopping energy. It then categorizes the main types of ballistic protective materials as hard body armor, which deflects projectiles, and soft body armor, which is preferred for its flexibility and comfort. The document concludes by discussing various fiber materials, weaves, and finishes used for optimal ballistic protection in personal armor.
orthodontic wires
types of wires
classification of wires
properties of wires
arch form
stainless steel wires and types
classification of stainless steel wires
This document provides information on carbon fiber reinforced polymer (CFRP) composites. It discusses the production of CFRP through various molding techniques like vacuum bagging and compression molding. It also covers the properties of CFRP composites like their light weight and high strength compared to other materials. Some disadvantages of CFRP like their high cost are also mentioned. Applications of CFRP composites in the aerospace, automotive and defense industries are summarized.
This document provides an overview of the general properties of orthodontic wire. It discusses the atomic arrangements of metallic materials used in orthodontics including face centered cubic, body centered cubic, and hexagonal close-packed structures. It also covers mechanical properties such as stress, strain, modulus of elasticity, stiffness, resilience and formability. Additional topics include work hardening, heat treatment, commonly used wire materials like stainless steel, nickel-titanium, and beta titanium alloys.
The document analyzes the performance of different prototype mooring hawsers manufactured with various constituent materials. Four prototypes were tested: 100% polyamide, 100% polyester, a hybrid of polyamide core and polyester jacket, and another hybrid with a different polyester. Dimensional properties and breaking strengths were measured, with all prototypes meeting international standards. The hybrid ropes performed better than 100% polyamide or polyester ropes, potentially offering longer service life.
TE-3113-7.pdf mechanics of fibrous Structure slidesNTU Faisalabad
This document provides an overview of mechanics of fibrous structures, specifically focusing on yarn structure. It discusses key aspects of yarn structure including fiber compactness, fiber arrangement, and fiber mobility. Fiber compactness influences yarn properties like strength and hand feel. Fiber arrangement impacts properties like strength and dimensional stability. Fiber mobility within yarns influences pilling resistance and other performance characteristics. The document also discusses different yarn types and theoretical models for predicting yarn tensile strength based on fiber and filament properties.
Unit 1-Introduction to Composites.pptxrohanpanage1
Composite materials can be summarized as follows:
1. Composite materials consist of a matrix and reinforcement, where the reinforcement is embedded within the matrix to improve its properties. Composites take advantage of the strengths of both materials.
2. Composites are classified based on their matrix, which can be polymer, metal, or ceramic. They are also classified based on the type of reinforcement, which can be particles, fibers, whiskers, or structural.
3. The matrix holds the reinforcement in place and protects it, while the reinforcement improves properties like strength and stiffness. Together they provide benefits like weight reduction, durability, and design flexibility compared to traditional materials.
This document discusses different types of natural fibers that can be used to make composites, including plant fibers like jute, banana, and stem fibers; animal fibers like wool and silk; and mineral fibers like asbestos. It provides details on the properties and processing of select natural fibers like jute, banana, and wool fibers. The applications and advantages of natural fiber composites are also mentioned.
UIET KUK MED Time table Jan to May 2024.pdfupender3
The document contains a timetable for the Mechanical Engineering Department of UIET. It lists the time slots and lecture numbers for different courses on various days of the week. It also lists the faculty members teaching different courses and time slots allocated for labs. The timetable is divided into sections for undergraduate courses on top and postgraduate/research courses at the bottom. It provides a comprehensive overview of class and lab schedules for all courses in the department.
The document outlines a course on Condition Monitoring. The course aims to teach students how to understand vibration causes and faults, and apply monitoring techniques like oil analysis, vibration monitoring, and other diagnostic methods to identify issues and develop effective maintenance schemes for industries. Students will learn oil analysis to diagnose wear debris, nonconventional diagnostic methods, modern maintenance technologies, and apply vibration monitoring to identify system issues over 3 lecture hours for 3 credits, assessed through major and minor tests.
Inspection using Liquid penetrant testing.pptxupender3
This document outlines standards and procedures for inspecting DPT including acceptable standards, personal qualifications, indications for inspection, evaluations of indications, acceptance criteria, and repair criteria. Key areas covered are the qualifications of inspectors, what should trigger an inspection, how inspections should be evaluated, and what criteria determine if repairs are needed.
A creep test subjects a specimen to a constant load and temperature over time to measure deformation. There are three creep stages: primary creep where the rate is rapid and decreases over time, secondary creep where the rate is relatively uniform, and tertiary creep where the rate accelerates until rupture. Creep tests are used to determine design parameters like steady-state creep rate and rupture lifetime. Stress rupture tests are similar but impose higher stresses to measure time to fracture. Data from creep tests are used to extrapolate lifetimes at different conditions using methods like the Larson-Miller parameter.
Phase diagrams provide information about the equilibrium conditions and transformations between different phases in a material system. They describe how the phases of a material vary with changes in temperature, pressure, and composition.
This document discusses key concepts related to phase diagrams including phases, the Gibbs phase rule, one-component and binary phase diagrams, eutectic and peritectic reactions, intermediate phases, ternary diagrams, and lever rule. It provides examples of phase diagrams for common material systems like water, Cu-Ni, Pb-Sn, Mg-Pb, and Cu-Zn. Cooling curves are also explained to illustrate phase transformations.
Fatigue refers to damage accumulated through repeated cyclic stresses over time. It is affected by factors like stress type/amplitude, surface finish, material properties, and environment. Fatigue life depends on the mean and amplitude of stresses based on relationships like the Goodman diagram. The Miner's rule states that the fraction of fatigue life consumed by stresses must be less than 1 to avoid failure. Fatigue tests involve repeated cyclic loading in tension, compression, bending, or other patterns to determine fatigue properties.
Creep is a time-dependent deformation of materials that occurs when they are subjected to high temperatures and/or constant stress over long periods of time. It involves the gradual deformation of materials as atoms slowly migrate and rearrange. Creep can lead to sudden fracture or impaired usefulness of structural components. The creep strength of a material represents the highest stress it can withstand over time without exceeding a specified creep strain. Creep behavior is determined through tests that apply different stress levels to specimens at constant temperature and measure the time to failure. Fatigue is the failure of materials caused by repetitive cyclic stresses, even if the stresses are below the yield strength. It can be quantified using an S-N curve, which plots the stress amplitude against the number
The document discusses time-temperature-transformation (TTT) diagrams, which show the microstructural phases that form in steels at different temperatures over time. In contrast to equilibrium phase diagrams, TTT diagrams account for nonequilibrium cooling rates. They indicate that at higher temperatures, pearlite forms with slow cooling, while faster cooling produces bainite or martensite. The document includes an example TTT diagram for eutectoid steel and explains how isothermal experiments at different temperatures are used to construct these diagrams.
Crystal defects can be classified based on their geometry. Point defects are zero-dimensional and include vacancies, interstitials, and impurities. Line defects are one-dimensional dislocations such as edge and screw dislocations. Surface defects are two-dimensional and include grain boundaries and stacking faults. Volume defects are three-dimensional such as cracks, voids, and inclusions. Real crystals always contain imperfections that influence material properties. Understanding crystal defects is important for both analyzing material behavior and developing techniques to minimize their impact.
1) Proper design of the gating system is important for solidification and depends on factors like mold geometry, metal flow, and heat transfer.
2) The gating system includes components like the sprue, runner, and ingate and is designed based on principles of fluid flow like Bernoulli's theorem and the law of continuity.
3) Risers are used to prevent shrinkage voids and their design must ensure the riser remains molten until solidification is complete to feed the casting. The size and placement of risers depends on properties of the casting like its shape and surface area to volume ratio.
Polymers are large molecules composed of repeating subunits called monomers. They can be natural or synthetic. Common synthetic polymers include plastics, nylon, and latex. Polymers are used in many applications because they are lightweight, strong, and inexpensive. They consist of long chains of monomers that can interact through entanglement and cross-linking to form durable materials.
Ultrasonic testing uses high frequency sound waves to detect surface and subsurface defects. It can be used to inspect thick sections non-destructively. There are different modes of wave propagation including longitudinal, transverse, surface waves and Lamb waves. Factors like frequency, penetration depth and scattering affect ultrasonic testing. It is widely used in manufacturing and service industries to inspect welds and structural metals.
The document provides information on heat treatment processes and the fundamentals of heat treatment of metals. It discusses the Fe-C equilibrium diagram and various phases in steel like ferrite, cementite, austenite, and pearlite. It describes the microstructure and properties of these phases. It also covers heat treatment processes like annealing, normalizing, hardening and discusses methods of surface hardening, heat treatment of cast irons and nonferrous metals. Various heat treatment parameters and objectives are defined. Diagrams of phase transformations and microstructures are included.
Point defects, such as vacancies and interstitials, are zero-dimensional imperfections in crystals. Line defects called dislocations are one-dimensional imperfections caused by a disruption of the stacking of atomic planes along a line. Dislocations can be edge or screw types. Surface imperfections are two-dimensional and include grain boundaries between crystals of different orientations, as well as twin boundaries and stacking faults. Volume imperfections are three-dimensional and include cracks, voids, and non-crystalline regions in a crystal. The presence of defects increases the potential energy of crystals.
A review on techniques and modelling methodologies used for checking electrom...nooriasukmaningtyas
The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELgerogepatton
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
represents a multi-tiered application layer protocol extensively utilized in Supervisory Control and Data
Acquisition (SCADA)-based smart grids to facilitate real-time data gathering and control functionalities.
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Composite_introduction.pdf
1. AE-681 Composite Materials
Instructor: Dr PM Mohite
Instructor: Dr. PM Mohite
Office: AE-11, Aerospace Engineering
Email: mohite@iitk.ac.in
Ph: 6024
Course Credits: 4
LTPD: 3-0-0-0
Course Content:
• Introduction Definition classification behaviors of unidirectional composites
• Introduction, Definition, classification, behaviors of unidirectional composites
• Analysis of lamina; constitutive classical laminate theory, thermal stresses,
• Design consideration, analysis of laminates after initial failure, interlaminar
t f t h i j i t d i t l h t i ti
stresses, fracture mechanics, joints and experimental characterization,
• Micromechanics
• Factors influencing strength and stiffness failure modes,
• Performance under adverse environment
• Prediction of strength, stiffness
2. AE-681 Composite Materials
Reference Books/Material:
Reference Books/Material:
• Mechanics of Fibrous Composites, CT Herakovich.
• Analysis and Performance of Fibre Composites, BD Agarwal and LJ Broutman.
• Mechanics of Composite Materials, RM Christensen.
• Any other book on composite materials
• Research papers
Grading Policy:
Midsem I + II: 40%
Midsem I + II: 40%
Assignments: 20% (Individual + Group)
Endsem: 40%
• Absolute 40% for passing. Relative grading after that.
• Assignments should be submitted on due date by 5.00 pm. Late submission
and copying will be heavily penalized !
• Attendance will be monitored regularly.
4. Composite: Formal Definition and History
What is composite?
What is composite?
Definition:
• A material which is composed of two or more materials at a microscopic scale
d h h i ll di ti t h
and have chemically distinct phases.
• Heterogeneous at a microscopic scale but statically homogeneous at
macroscopic scale.
• Constituent materials have significantly different properties.
Classification of certain materials as a composite:
1. Combination of materials should result in significant property changes
2 Content of the constituents is generally more than 10%
2. Content of the constituents is generally more than 10%
3. In general, property of one constituent is much greater (≥ 5) than the other
5. Composite: Formal Definition
History: Oldest application/existence of composite material?
History: Oldest application/existence of composite material?
4000 B.C. – laminated writing material from the papyrus plant
1300 B.C. – Egyptians and Mesopotamian used straw bricks
1200 A.D. - Mongols invented the first composite bow
6. Composite: Formal Definition and History
Composite Bow dates back to 3000 BC (Angara Dating)
Composite Bow – dates back to 3000 BC (Angara Dating)
Materials Used:
Wood, Horn, Sinew (Tendon), Leather, Bamboo
and Antler (Deer horn)
Horn and Antler: naturally flexible and resilient
Sinews: back tendons or hamstrings of cows and deer
Glue: From bladder of fish
Strings: Sinew, Horse hair, Silk
Overall processing time was almost a year !
Source: http://medieval2.heavengames.com
7. Composite: Formal Definition and History
Composite Bow dates back to 3000 BC (Angara Dating)
Composite Bow – dates back to 3000 BC (Angara Dating)
9. Composite: Examples from Day-to-Day Life
Examples:
Examples:
1. Straw-bricks
2. Concrete
3. Wood
(cellulose + lignin)
4. Human body
(muscles + bones)
5. Tyres
6 Plywood
6. Plywood
7. Sports good ……………………
10. Evolution of Materials
Use of Modern (Polymer) Composites:
Use of Modern (Polymer) Composites:
During World War II –
Military application
Non-metallic shielding of Radomes
(to house electronic radar equipments)
Glass Fibre Reinforced Plastics (GFRP)
The first application of wood - composite laminates in -
Havilland Mosquito Fighter/Bomber of British Royal Air-Force
11. Evolution of Materials
Use of Modern (Polymer) Composites:
Use of Modern (Polymer) Composites:
During World War II –
Attack on Pearl Harbour by Japanese
Torpedo bomber
Sopwith Cuckoo Fairey Swordfish
Source: http://en.wikipedia.org/wiki/Torpedo_bomber
12. Composite: Necessicity
Why do you need composite materials?
Why do you need composite materials?
Enhanced desired properties !
What are these desired properties?
• Strength
• Stiffness
• Toughness
• Corrosion resistance
• Wear resistance
• Wear resistance
• Reduced weight
• Fatigue life
• Thermal/Electrical insulation and conductivity
• Acoustic insulation
• Energy dissipation
• Attractiveness, cost, ……………………..
•Tailorable properties
16. Composite: Constituents
What are the constituents in a composite material?
What are the constituents in a composite material?
1. Reinforcement:
discontinuous
stronger
harder
2. Matrix:
Continuous
Continuous
What are the functions of a reinforcement?
1. Contribute desired properties
2. Load carrying
3. Transfer the strength to matrix
17. Composite: Constituents
What are the functions of a matrix?
What are the functions of a matrix?
1. Holds the fibres together
2. Protects the fibres from environment
3. Protects the fibres from abrasion (with each other)
4. Helps to maintain the distribution of fibres
5. Distributes the loads evenly between fibres
6. Enhances some of the properties of the resulting material and structural
component (that fibre alone is not able to impart). These properties are
component (that fibre alone is not able to impart). These properties are
such as:
transverse strength of a lamina
Impact resistance
Impact resistance
7. Provides better finish to final product
19. Classification of Composites
Based on the form of reinforcement
Based on the form of reinforcement
• Fibre - a filament with L/D very high (of the order 1000)
• Fibre - a filament with L/D very high (of the order 1000)
• A composite with fibre-reinforcement is called Fibrous Composite
• Particle – non fibrous with no long dimension
• A composite with particles as reinforcement is called Particulate Composite
• Whiskers – nearly perfect single crystal fibre
• Short, discontinuous, polygonal cross-section
22. Fibres as a Reinforcement
Fibre reinforced composites is the interest of this course !
Fibre reinforced composites is the interest of this course !
Why do you make fibre reinforcements of a thin diameter?
1. As the diameter decreases the inherent flaws in the material
also decreases and the strength increases.
E De Lamotte, AJ Perry. Fibre Science and Technology, 1970;3(2):157-166.
23. Fibres as a Reinforcement
2 For better load transfer from matrix to fibre composites require larger
2. For better load transfer from matrix to fibre composites require larger
surface area of the fibre matrix interface.
Fib t i i t f A N D L
Fibre matrix interface area: A = N π D L
(N – No. of fibres, D – fibre diameter, L – length of fibres)
Replace D by d (smaller diameter fibres)
For same Fibre Volume Fraction*: n = N(D/d)2
For same Fibre Volume Fraction : n N(D/d)
New fibre matrix interface area: A = N π D2 L/d = 4 * Volume of fibres / d
Thus, for a given fibre volume fraction, the area of the fibre-matrix interface is
inversely proportional to the diameter of the fibre.
* Fibre Volume Fraction (Vf) = Volume of fibres/Volume of composite
Matrix Volume Fraction (Vm) = Volume of matrix/Volume of composite
Vf + Vm = 1
24. Fibres as a Reinforcement
3 The fibres should be flexible/pliant so that they can be bend easily without
3. The fibres should be flexible/pliant so that they can be bend easily without
breaking. For example, woven fibre composites needs flexible fibres.
Fl ibilit i d fi d i f b di tiff
Flexibility is defined as inverse of bending stiffness.
Consider a fibre as beam under pure bending, then
EI – Bending stiffness or Flexural rigidity
Flexibility α 1/EI
Flexibility α 1/EI
where, I = π d4/64
Flexibility α 1/Ed4
Thus, flexibility of a fibre is inversely proportional to 4th power of the fibre
diameter.
25. Types of Fibres
1 Advanced Fibres:
1. Advanced Fibres:
Fibres possessing high specific stiffness [E/ρ] and specific strength [σ/ρ])
a) Glass
b) Carbon
c) Organic
c) Organic
d) Ceramic
28. Advanced Fibres
Glass fibres:
Glass fibres:
• ancient Egyptians made containers from coarse fibres drawn from heat-
softened glass
d d b t di lt l t 1200ºC
• produced by extruding molten glass at 1200ºC
• passed through spinnerets of 1-2 mm diameter
• then drawing the filaments to produce fibres of diameter between 1-5 μm
• individual filament is small in diameter, isotropic in behaviour and very
flexible
• variety of forms:
E glass: high strength and high resistivity
S2 glass: high strength, modulus and stability under extreme
temperature, corrosive environment
e pe u e, co os ve e v o e
R glass: enhanced mechanical properties
C glass: resists corrosion in an acid environment
D glass: dielectric properties
D glass: dielectric properties
• In general, glass fibres are isotropic in nature
29. Advanced Fibres
Carbon fibres:
Carbon fibres:
• carbon- carbon covalent bond is the strongest in nature
Guess who made the first carbon fibre?
Thomas Edison made carbon fibre from bamboo when
experimenting for light bulb !
What is the difference between carbon and graphite fibres?
- Carbon fibre contains 80-95 % of carbon and graphite fibre contains
more than 99% carbon
- carbon fibre is produced at 1300ºC while graphite fibre is produced
in excess of 1900ºC
Caution ! - In general term carbon fibre is used for both fibres
Made from two types of precursor materials:
Made from two types of precursor materials:
1) Polyacrylonitrile (PAN) (PAN Based)
2) Rayon Pitch - residue of petroleum refining (Pitch Based)
30. Advanced Fibres
Carbon fibres:
Carbon fibres:
• Precursor fiber is carbonized rather then melting
• Filaments are made by controlled pyrolysis (chemical deposition by heat) of a
t i l i fib f b h t t t t t t t 1000 3000º C
precursor material in fiber form by heat treatment at temperature 1000-3000º C
• Different fibers have different morphology, origin, size and shape. The
morphology is very dependent on the manufacturing process.
• The size of individual filament ranges from 3 to 14 µm. Hence, very flexible.
• Maximum temperature of use of the fibers ranges from 250 ºC to 2000 ºC.
Properties changes with temperature at higher temperature.
• The maximum temperature of use of a composite is controlled by the use
temperature of the matrix
• Modulus and strength is controlled by the process-thermal decomposition of the
organic precursor under well controlled conditions of temperature and stress
• Heterogeneous microstructure consisting of numerous lamellar ribbons
• Thus, carbon fibers are anisotropic in nature
, p
31. Advanced Fibres
Organic fibres: Aramid fibres
Organic fibres: Aramid fibres
• Aromatic polyamide – family of nylons.
• Polyamide 6 = nylon 6, Polyamide 6.6 = nylon 6.6
• Melt-spun from a liquid solution
• Morphology – radially arranged crystalline sheets resulting into anisotropic
properties
• Filament diameter about 12 µm and partially flexible
• High tensile strength
• Intermediate modulus
Intermediate modulus
• Very low elongation up to breaking point
• Significantly lower strength in compression
• D P t d l d th fib d th t d K l F l (
• Du Pont developed these fibers under the trade name Kevlar. From poly (p-
Phenylene terephthalamide (PPTA) polymer
• 5 grades of Kevlar with varying engineering properties are available
kevlar-29, Kevlar-49, Kevlar-100, Kevlar-119, Kevlar-129
32. Advanced Fibres
Ceramic Fibres: Boron
Ceramic Fibres: Boron
It was the first advanced fibre developed for structural application (Talley 1959)
• Ceramic monofilament fiber
• Manufactured by CVD on to a tungsten core of 12 µm diameter
Tungsten
Boron
Boron
• Fiber itself is a composite
• Circular cross section
• Fiber diameter ranges between 33 -400µm and typical diameter is 140µm
• Boron is brittle hence large diameter results in lower flexibility
CP Talley. J. Appl. Phys. 1959, Vol. 30, pp 1114.
33. Advanced Fibres
Ceramic Fibres: Boron
Ceramic Fibres: Boron
• Thermal coefficient mismatch between boron and tungsten results in thermal
id l t d i f b i ti l d t t t
residual stresses during fabrication cool down to room temperature
• When coated with Sic or B4C can be used to reinforce light alloys
• Strong in both tension and compression
• Exhibit linear axial stress-strain relationship up to 650ºC
• High cost of production
34. Advanced Fibres
Ceramic fibres: Alumina (Al O )
Ceramic fibres: Alumina (Al2O3)
• These are ceramics fabricated by spinning a slurry mix of alumina particles and
dditi t f hi h i th bj t d t t ll d h ti
additives to form a yarn which is then subjected to controlled heating.
• Fibers retain strength at high temperature
35. Advanced Fibres
Ceramic fibres: Silicon Carbide (SiC)
Ceramic fibres: Silicon Carbide (SiC)
First method: CVD on tungsten or carbon
- Carbon – pyrolytic graphite coated carbon core SCS-6
- This fiber is similar in size and microstructure to boron
- Relativity stiff, size of 140 µm
Second method: (Nicalon by Japan)
- Controlled pyrolysis (chemical deposition by heat) of a polymeric
- Controlled pyrolysis (chemical deposition by heat) of a polymeric
precursor
- filament is similar to carbon fiber in size.
Si ≈ 14
- Size ≈ 14 µm
- more flexible
• SiC shows high structural stability and strength retention even at temperature
above 1000ºC
37. Shape Examples
Cross Sectional Shapes of Fibres
Shape Examples
Hexagonal:
Sapphire (Al2O3) whiskers
Rounded Trianagular:
g
Sapphire (Al2O3) single crystal fibre
Kideney bean:
Carbon
Trilobal:
Carbon, Rayon
38. Types of Matrix Materials
Polymers:
Polymers:
Thermoplastic: Soften upon heating and can be reshaped with heat &
pressure
Th tti b li k d d i f b i ti & d t
Thermosetting: become cross linked during fabrication & do not
soften upon reheating
Metals:
Ceramics:
Carbon and Graphite:
39. Types of Matrix Materials
Thermoplastics:
Thermoplastics:
polypropylene,
polyvinyl chloride (PVC),
nylon,
polyurethane,
poly-ether-ether ketone (PEEK),
polyphenylene sulfide (PPS),
polysulpone
• higher toughness
• high volume
• low- cost processing
• Temperature range ≥ 225ºC
40. Types of Matrix Materials
Thermoplastics:
Thermoplastics:
Thermoplastics are increasingly used over thermosets becuase of the following
reasons:
• Processing is faster than thermoset composites since no curing reaction is
required. Thermoplastic composites require only heating, shaping and cooling.
• Better properties:
- high toughness (delamination resistance) and damage tolerance,
- low moisture absorption
- chemical resistance
• They have low toxity.
• Cost is high !
41. Types of Matrix Materials
Thermosets:
Thermosets:
polyesters,
epoxies,
polyimides
Other resins
Polyesters:
• Low cost
• Good mechanical strength
• Good mechanical strength
• Low viscosity and versatility
• Good electrical properties
• Good heat resistance
• Cold and hot molding
• Curing temperature is 120°C
42. Types of Matrix Materials
Thermosets:
Thermosets:
Epoxy:
• Epoxy resins are widely used for most advanced composites.
Advantages:
• Low shrinkage during curing
• High strength and flexibility
• High strength and flexibility
• Adjustable curing range
• Better adhesion between fibre and matrix
• Better electrical properties
• Resistance to chemicals and solvents
43. Types of Matrix Materials
Thermosets:
Thermosets:
Epoxy:
Disadvantages:
• somewhat toxic in nature
• limited temperature application range upto 175°C
• moisture absorption affecting dimensional properties
• high thermal coefficient of expansion
• high thermal coefficient of expansion
• slow curing
44. Types of Matrix Materials
Thermosets:
Thermosets:
Polyimides:
• Excellent mechanical strength
• Excellent strength retention for long term in 260-315°C (500-600°F) range
and short term in 370°C (700°F) range
• Excellent electrical properties
• Good fire resistance and low smoke emission
• Hot molding under pressure and
Hot molding under pressure and
• Curing temperature is 175°C (350°F) and 315°C
45. Types of Matrix Materials
Problems with using polymer matrix materials:
Problems with using polymer matrix materials:
• Limited temperature range
• Susceptibility to environmental degradation due to moisture, radiation,
atomic oxygen (in space)
• Low transverse strength
• High residual stress due to large mismatch in coefficients of thermal
expansion both fiber and matrix
• Polymer matrix can not be used near or above the glass transition
temperature
46. Types of Matrix Materials
Metals:
Metals:
Aluminum
Titanium
Copper
• Higher use temperature range
Aluminum matrix composite – use temperature range above 300ºC
and titanium at 800 ºC
• Higher transfer strength, toughness( in contrast with brittle behavior of
Higher transfer strength, toughness( in contrast with brittle behavior of
polymers and ceramics)
• The absence of moisture & high thermal conductivity (copper)
Disadvantages:
• Heavier
• More susceptible to interface degradation at the fiber/matrix interface and to
corrosion
47. Types of Matrix Materials
Ceramics:
Ceramics:
Carbon,
Silicon carbide and
Silicon nitride
• Ceramic have use very high temperature range > 2000 ºC
• High elastic modulus
• Low density
Disadvantages:
• brittleness
• Susceptible to flows
48. Types of Matrix Materials
Carbon:
Carbon:
carbon fibres in carbon matrix – carbon/carbon composites
used under extreme mechanical and thermal loads (space applications)
Advantages:
• Low specific weight
• High heat absorption capacity
• Resistance to thermal shock
• High resistance to damage
• Exceptional frictional properties at high energy levels
• Exceptional frictional properties at high energy levels
• Resistance to high temperatures
• Chemical inertness
• low coefficient of thermal expansion (excellent dimensional stability)
Disadvantages:
• low resistance to oxidation above 500°C
• high cost of materials and manufacturing
50. Forms of Fibrous Composites
Layered composites:
Layered composites:
Layer
Lamina any of the term is used
Ply
Axial – along fibre length (1)
Transverse – perpendicular
Transverse – perpendicular
to fibre length
2 – in-plane transverse
3 – out of plane transverse
51. Forms of Fibrous Composites
Layered composites:
Layered composites:
Laminate
52. Forms of Fibrous Composites
Woven Bi directional composite:
Woven Bi-directional composite:
Three types of weave
Our interest is lamina and laminate !
http://www.britannica.com/EBchecked/topic/638448/weaving
53. Types of Fibrous Composites
Fibre and Matrix Systems:
Fibre and Matrix Systems:
Notation:
fibre/matrix
carbon/epoxy, glass/epoxy, Kevlar/epoxy
proportion of contents must be mentioned (volume fraction)
Examples:
AS4/PEEK
AS4/PEEK,
T300/5208
T700/M21
Carbon Composites
IM8/Epoxy
Kevlar/Epoxy
Boron/Al
SCS-6/Ti-15-3
S2 Glass/Epoxy
54. Properties of Fibrous Composites
• Reduction in properties
• Reduction in properties
Compared to reinforcement
properties
• Axial along fibre length
• Transverse perpendicular
to fibre
• Degree of orthotropy
55. Properties of Fibrous Composites
Parameters affecting the properties of fibrous composites:
Parameters affecting the properties of fibrous composites:
1. Length of the fibre
2. Orientation of the fibre (with respect to the loading direction)
3. Shape of the fibre
4 Distribution of the fibres in matrix material
4. Distribution of the fibres in matrix material
5. Properties of the fibres
6. Properties of the matrix material
7. Proportion of fibre and matrix material
56. Factors Affecting Fabrication Processes
1 i
1. User requirements
2. Performance requirements
3. Total production volume
4. Production rate
5. Cost of production
6. Size of the production
7. Surface finish of the final product
8. Geometry of the product
9. Material
57. Fabrication Processes of Fibrous Composites
• More than 50 processes depending upon the fibre and matrix type and nature
• More than 50 processes depending upon the fibre and matrix type and nature
• Wet/Hand Lay-Up
• Spray Lay-Up
• Vacuum Bagging
• Filament Winding
• Pultrusion
• Resin Transfer Molding (RTM)
• Braiding
• Braiding
• Vacuum Assisted RTM
• Centrifugal Casting
58. Fabrication Processes of Fibrous Composites
• Wet/Hand Lay Up
• Wet/Hand Lay-Up
Source: http://www.gurit.com
59. Fabrication Processes of Fibrous Composites
• Spray Lay Up
• Spray Lay-Up
Source: http://www.gurit.com
77. Disadvantages of Composite Materials
1 High cost of raw materials and fabrication
1. High cost of raw materials and fabrication.
2. Composites are brittle and thus are more easily damagable.
3. Transverse properties may be weak.
4. Matrix is weak, therefore, low toughness.
5. Reuse and disposal may be difficult.
6. Health hazards during manufacturing , during and after use.
7. Joining to parts is difficult
8. Repair introduces new problems, for the following reasons:
• Materials require refrigerated transport and storage and have
• Materials require refrigerated transport and storage and have
limited shelf life.
• Hot curing is necessary in many cases requiring special tooling.
C i t k ti
• Curing takes time.
9. Analysis is difficult.
10. Matrix is subject to environmental degradation
78. References and Additional Reading
1 MF Ashby Technology of the 1990s: advanced materials and predictive design
1. MF Ashby. Technology of the 1990s: advanced materials and predictive design.
Philosophical Transactions of Royal Society of London A. 1987;322:393-407.
2. LC Hollaway. The evolution of and the way forward for advanced polymer
composites in civil infrastructure Construction and Building Materials
composites in civil infrastructure. Construction and Building Materials.
2003;17:365-378.
3. KK Chawla. Fibrous Materials. Cambridge University Press, 1998.
4 htt // i / it /
4. http://www.owenscorning.com/composites/
5. http://www.gurit.com/
6. http://www.hexcel.com/
7. http://www.toray.com/
82. Natural Fibres
Vegetable fibres:
Vegetable fibres:
Hemp:
Long fibres about 2 m in length
Lustrous like linen with special processing
Strong and durable. Used for twine, yarn, rope
string
string
Used as artificial sponge