This document summarizes a micromechanical analysis of a hybrid composite with carbon and Dyneema SK-60 fibers done using finite element analysis in ABAQUS. Different fiber volume fractions were studied. The analysis obtained stiffness and strength properties. Results showed the first fiber to fail longitudinally in each unit strain case, with carbon failing first in most cases except strain in the z-direction, where Dyneema failed first.
The document discusses how to calculate key properties of particle and fiber composites. It explains how to determine the critical and ideal fiber lengths, as well as how to calculate the longitudinal and transverse stresses, strains, and elastic moduli of fiber composites. The objectives are to learn calculations for the upper and lower bounds of a particle composite's Young's modulus, the critical fiber length, and the strength of the fiber-matrix bond or matrix shear strength for a fiber composite.
This document discusses a project to develop an extruder head capable of 3D printing fiber reinforced thermoplastic composites. A team of 5 mechanical engineering students from Colorado State University, advised by Dr. Don Radford, aims to combine the structural properties of composites with the manufacturing simplicity of additive manufacturing. The document provides background on composites properties, manufacturing techniques, and the goals and work plan for the project, which includes designing and testing an extruder head that can consolidate thermoplastic composites during additive manufacturing.
This document discusses composites, which are materials made from two or more constituent materials with different physical or chemical properties. It describes different types of composites including fiber reinforced plastics, concrete, wood, and others. It focuses on fiber reinforced plastic composites, discussing different fiber types like glass, carbon, and aramid fibers and how they are produced and their mechanical properties. It also discusses matrix materials like polyester and epoxy resins and how they contribute to the properties of fiber reinforced composites. The properties and applications of different composites are summarized.
The document discusses unidirectional fiber reinforced composites and their properties. It notes that while these composites are very strong in the fiber direction, they are weak transverse to the fibers due to stress concentrations at the fiber-matrix interface. For applications with loads in unknown or varying directions, laminates with fibers oriented in multiple directions are needed. The document then focuses on short fiber reinforced composites, which can provide isotropic in-plane properties at a lower cost than unidirectional composites. It describes the production of alumina-silica fibers via a sol-gel process and their properties.
The document summarizes a study on the effect of reinforcement dimensions on the vibration characteristics of polypropylene composites. Finite element analysis was conducted to predict the interfacial stress distribution of long single fiber and short multi-fiber models at different volume fractions. Experimental testing of unreinforced, long glass fiber reinforced, and short glass fiber reinforced polypropypylene materials was also performed to analyze damping behavior under forced vibrations. The results of the finite element analysis aim to provide composites with greater interfacial strength, leading to increased ability to absorb shocks and vibrations without damage. Preliminary experimental findings indicate that short fiber reinforced polypropylene exhibits higher damping capacity than long fiber reinforced polypropylene.
Tensile behavior of environment friendly jute epoxy laminatedDr. Rashnal Hossain
This document summarizes research on developing jute fiber-reinforced epoxy composite laminates with different fiber orientations and evaluating their tensile and bending properties. Jute-epoxy composites were fabricated using vacuum assisted resin infiltration with jute preforms arranged in 0/0/0/0, 0/+45/-45/0, and 0/90/90/0 stacking sequences. Tensile and three-point bend tests showed the longitudinal tensile strength was highest for the 0/0/0/0 laminate and decreased with increasing fiber angle. Transverse properties increased with fiber angle. Fracture analysis found failures were due to matrix cracking, fiber/matrix debonding, and fiber pullout
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.
The document discusses how to calculate key properties of particle and fiber composites. It explains how to determine the critical and ideal fiber lengths, as well as how to calculate the longitudinal and transverse stresses, strains, and elastic moduli of fiber composites. The objectives are to learn calculations for the upper and lower bounds of a particle composite's Young's modulus, the critical fiber length, and the strength of the fiber-matrix bond or matrix shear strength for a fiber composite.
This document discusses a project to develop an extruder head capable of 3D printing fiber reinforced thermoplastic composites. A team of 5 mechanical engineering students from Colorado State University, advised by Dr. Don Radford, aims to combine the structural properties of composites with the manufacturing simplicity of additive manufacturing. The document provides background on composites properties, manufacturing techniques, and the goals and work plan for the project, which includes designing and testing an extruder head that can consolidate thermoplastic composites during additive manufacturing.
This document discusses composites, which are materials made from two or more constituent materials with different physical or chemical properties. It describes different types of composites including fiber reinforced plastics, concrete, wood, and others. It focuses on fiber reinforced plastic composites, discussing different fiber types like glass, carbon, and aramid fibers and how they are produced and their mechanical properties. It also discusses matrix materials like polyester and epoxy resins and how they contribute to the properties of fiber reinforced composites. The properties and applications of different composites are summarized.
The document discusses unidirectional fiber reinforced composites and their properties. It notes that while these composites are very strong in the fiber direction, they are weak transverse to the fibers due to stress concentrations at the fiber-matrix interface. For applications with loads in unknown or varying directions, laminates with fibers oriented in multiple directions are needed. The document then focuses on short fiber reinforced composites, which can provide isotropic in-plane properties at a lower cost than unidirectional composites. It describes the production of alumina-silica fibers via a sol-gel process and their properties.
The document summarizes a study on the effect of reinforcement dimensions on the vibration characteristics of polypropylene composites. Finite element analysis was conducted to predict the interfacial stress distribution of long single fiber and short multi-fiber models at different volume fractions. Experimental testing of unreinforced, long glass fiber reinforced, and short glass fiber reinforced polypropypylene materials was also performed to analyze damping behavior under forced vibrations. The results of the finite element analysis aim to provide composites with greater interfacial strength, leading to increased ability to absorb shocks and vibrations without damage. Preliminary experimental findings indicate that short fiber reinforced polypropylene exhibits higher damping capacity than long fiber reinforced polypropylene.
Tensile behavior of environment friendly jute epoxy laminatedDr. Rashnal Hossain
This document summarizes research on developing jute fiber-reinforced epoxy composite laminates with different fiber orientations and evaluating their tensile and bending properties. Jute-epoxy composites were fabricated using vacuum assisted resin infiltration with jute preforms arranged in 0/0/0/0, 0/+45/-45/0, and 0/90/90/0 stacking sequences. Tensile and three-point bend tests showed the longitudinal tensile strength was highest for the 0/0/0/0 laminate and decreased with increasing fiber angle. Transverse properties increased with fiber angle. Fracture analysis found failures were due to matrix cracking, fiber/matrix debonding, and fiber pullout
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.
This document discusses composites, which are materials made from two or more constituent materials with different physical or chemical properties. It describes different types of composites including fiber reinforced plastics, concrete, wood, and others. It focuses on fiber reinforced plastic composites, discussing different fiber types like glass, carbon, and Kevlar fibers and how they are produced and used to reinforce plastic matrices. It also addresses properties of fiber reinforced plastics and equations for calculating properties of composite materials.
This document introduces concepts of stiffness and strength in fiber-reinforced composite materials. It discusses:
1) Composites consist of a matrix reinforced with fibers, such as glass or carbon fibers in a polymer matrix. The fibers have much higher strength and stiffness than traditional materials.
2) The stiffness of a unidirectional composite in the fiber direction can be estimated using a rule of mixtures, based on the fiber and matrix properties and volume fractions. Transverse stiffness is estimated using a series model.
3) Fiber volume fraction, fiber and matrix properties, and fiber orientation determine the composite's anisotropic mechanical properties. Empirical models are used for more complex fiber arrangements.
4) Strength
Optimization of Heavy Vehicle Suspension System Using CompositesIOSR Journals
A leaf spring is a simple form of spring, commonly used for the suspension in wheeled vehicles. Leaf
Springs are long and narrow plates attached to the frame of a trailer that rest above or below the trailer's axle.
There are mono leaf springs, or single-leaf springs, that consist of simply one plate of spring steel. These are
usually thick in the middle and taper out toward the end, and they don't typically offer too much strength and
suspension for towed vehicles. Drivers looking to tow heavier loads typically use multi leaf springs, which
consist of several leaf springs of varying length stacked on top of each other. The shorter the leaf spring, the
closer to the bottom it will be, giving it the same semielliptical shape a single leaf spring gets from being thicker
in the middle. The automobile industry has shown increased interest in the replacement of steel spring with
fiberglass composite leaf spring due to high strength to weight ratio. In this thesis a leaf spring used in a heavy
vehicle is designed. While designing leaf spring following four cases are considered: by changing the thickness,
changing no. of leaves, changing camber and changing span .Present used material for leaf spring is Mild Steel.
The objective of this thesis is to compare the load carrying capacity, stiffness and weight savings of composite
leaf spring with that of steel leaf spring. The design constraints are stresses and deflections. In this thesis, the
material is replaced with composites since they are less dense than steel and have good strength. The strength
validation is done using FEA software ANSYS by structural analysis. Modal analysis is also done to determine
the frequencies. Analysis is done by layer stacking method for composites by changing number of layers 3, 5, 11
and 23. The composites used are Aramid Fiber and Glass Fiber
Analysis Of Lpg Cylinder Using Composite MaterialsIOSR Journals
This paper aims is innovation of alternative materials of Liquid petroleum gas (LPG). So, the finite
element analysis of Liquefied Petroleum Gas (LPG) cylinders made of Steel and Fiber Reinforced Plastic (FRP)
composites has been carried out. Finite element analysis of composite cylinder subjected to internal pressure is
performed. Layered shell element of a versatile FE analysis package ANSYS (version 11.0) has been used to
model the shell with FRP composites.
A number of cases are considered to study the stresses and deformations due to pressure loading inside the
cylinder. First, the results of stresses and deformation for steel cylinders are compared with the analytical
solution available in literature in order to validate the model and the software. The weight savings are also
presented for steel, Glass Fiber Reinforced Plastic (GFRP) composites LPG cylinders. Variations of stresses
and deformations throughout the cylinder made of steel and GFRP are studied.
IRJET- Experimental Evaluation of Glass Fiber Reinforced Composites Subjected...IRJET Journal
This document describes an experimental study that evaluated the mechanical properties of glass fiber reinforced composites subjected to different loads. Glass fiber reinforced laminates were manufactured using the hand layup technique with ten layers of glass fiber and epoxy resin. Standard tests were conducted to determine the tensile, compression, flexural, impact, and shear properties of the laminates according to ASTM standards. The experimental results were used to characterize the strength of the glass fiber reinforced composites and how they respond to different types of loads. The study found that glass fiber reinforced composites have superior mechanical properties compared to traditional materials making them suitable for applications in industries such as aerospace, marine, and defense.
This document provides a historical overview and introduction to composite materials. It discusses:
1) The early uses of natural fiber composites throughout history for applications like bows and buildings.
2) The modern revival and increasing use of composites in aircraft and spacecraft in the late 20th century to improve structural performance.
3) Future trends toward more integrated design processes, cost reduction, and use of natural fibers to make composites more environmentally friendly.
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.
The document discusses composites materials and their properties. Composites consist of fibers and a matrix bonded together to form a strong material. The properties of composites depend on the fiber type, fiber orientation, fiber length, fiber content, and the matrix used. Natural fibers have advantages over glass fibers in terms of cost, density and sustainability, but also have limitations like moisture absorption. Proper treatment of fibers can improve adhesion between the fiber and matrix. Different manufacturing techniques like hand layup, filament winding, pultrusion are used to produce composites depending on the end application.
Mumbai University.
Mechanical Engineering
SEM III
Material Technology
Module 6
Introduction to New materials:
6.1 Composites: Basic concepts of composites, Processing of composites, advantages over metallic materials, various types of composites and their applications
6.2 Nano Materials: Introduction, Concepts, synthesis of nanomaterials, examples, applications, and Nanocomposites
6.3 An overview to Smart materials (e.g.: Rheological fluids)
IRJET-Study of Properties of Banana Fiber Reinforced with Jute FiberIRJET Journal
1. The study investigates reinforcing banana fiber with jute fiber to improve its mechanical properties for increased usage.
2. Specimens of banana and jute fiber reinforced with epoxy resin were prepared and tested for tensile strength, flexural strength, and impact resistance.
3. The tensile strength was found to increase with increased fiber thickness, while the flexural and impact strengths improved by optimizing the fiber-resin composition. Reinforcing banana fiber with jute fiber shows potential for developing stronger, more durable natural fiber composites.
Energy Release Rate for Fiber Reinforced Polymer CompositeIOSRJAP
An experimental investigation using drag-out tensile test to calculate the interfacial shear strength for different embedded lengths and radius of Kevlar -49, carbon and ultra high polyethylene fibers reinforced epoxy matrix , the energy release rate calculated by using Nairn model . The energy release rate increase as the embedded fiber length increase and also for fiber radius for perfect adhesion , for specimens with bubbles at interface which seems to reduce the fracture toughness the energy release rate be less than specimens with perfect adhesion , the thermal stress and friction forces were included in the energy release rate in Kevlar-49 and carbon reinforced epoxy the interfacial shear force due to friction part decrease while in solid ultra high polyethylene the interfacial shear force due to friction part increase.
IRJET- Fabrication and Characterization of Jute/Glass Fibre Reinforced Epoxy ...IRJET Journal
This document discusses the fabrication and characterization of jute/glass fiber reinforced epoxy hybrid composites. Various composites with different weight percentages of jute and glass fibers were created using hand layup and epoxy resin. Tensile and bending tests found that composites with 20% jute and 20% glass fiber exhibited the highest tensile strength, while composites with 28% jute and 12% glass fiber showed the highest flexural strength. The study demonstrated that hybrid composites of jute and glass fibers can improve the mechanical properties of epoxy resin.
Testing the flexural fatigue behavior of e glass epoxy laminateseSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This document analyzes LPG cylinders made of steel and carbon fiber reinforced plastics (CFRP) composites using finite element analysis. It first validates the finite element model by comparing steel cylinder results to analytical solutions. Stress and deformation variations are then studied for steel and CFRP cylinders under internal pressure loading. CFRP composites are found to provide weight savings over steel cylinders while maintaining sufficient strength for LPG storage applications.
Composite materials are composed of two or more distinct materials that produce properties different from the individual components. They have advantages like high strength to weight ratio, better fatigue and toughness properties than metals, and resistance to corrosion. Composites consist of a primary matrix phase that holds a secondary reinforcing phase like fibers, particles, or flakes. The matrix provides shape while the reinforcement improves properties. Fiber reinforced polymer composites are an important class of materials.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Seminar on composite application in aerospace enggR.K. JAIN
This document discusses a seminar on composite materials for aerospace applications. It begins with an introduction to composite materials, including their classification and advantages. Composites are made of two or more distinct phases (a matrix and dispersed phase) that provide overall superior properties compared to individual components. The document then discusses the different types of composites like particulate reinforced, fiber reinforced, and structural composites. Applications in aerospace are also presented, like usage in Boeing 777 aircraft at 12%. The document concludes that composites will play an increasingly significant role in aerospace due to properties like low weight and high strength.
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 document discusses a study on improving the impact resistance of composite laminates by embedding shape memory nitinol (NiTi) wire. Specifically:
- Specimens were prepared with layers of SiC, Kevlar fabric, and PVC foam board, with and without embedded NiTi shape memory alloy (SMA) wires.
- Low velocity impact testing was performed using a gas gun. Results showed embedding SMA wires between the SiC and PVC layers improved impact resistance, with no deformation observed, as the superelastic SMA wires dissipated impact energy uniformly.
- Without SMA wires, the composite laminates showed increasing damage from bulging to piercing under impact. The SMA wires'
This document describes Article-Level Eigenfactor (ALEF), a method for ranking and mapping scholarly articles based on their citation networks. ALEF calculates citation scores for articles, author scores based on article scores, and blends the features to generate final scores. It was developed by researchers at the University of Washington and performs well compared to other ranking methods while being simple, fast, and providing high-resolution rankings. The researchers applied ALEF to the WSDM Cup Challenge on entity ranking and achieved a score of 0.699 in Phase I.
Tractor-trailers are used all across America to transport cargo, but are not designed with fuel efficiency in mind. Therefor, there is an incentive for companies to invest in making their tractor-trailers more aerodynamic in order to save on fuel costs. I go into the testing and methodology of how my team and I decided to tackle the problem of reducing the coefficient of drag on tractor-trailers by implementing air channeling devices (ACDs). Then, I cover the results from our experiments and our ACD recommendation.
This document discusses composites, which are materials made from two or more constituent materials with different physical or chemical properties. It describes different types of composites including fiber reinforced plastics, concrete, wood, and others. It focuses on fiber reinforced plastic composites, discussing different fiber types like glass, carbon, and Kevlar fibers and how they are produced and used to reinforce plastic matrices. It also addresses properties of fiber reinforced plastics and equations for calculating properties of composite materials.
This document introduces concepts of stiffness and strength in fiber-reinforced composite materials. It discusses:
1) Composites consist of a matrix reinforced with fibers, such as glass or carbon fibers in a polymer matrix. The fibers have much higher strength and stiffness than traditional materials.
2) The stiffness of a unidirectional composite in the fiber direction can be estimated using a rule of mixtures, based on the fiber and matrix properties and volume fractions. Transverse stiffness is estimated using a series model.
3) Fiber volume fraction, fiber and matrix properties, and fiber orientation determine the composite's anisotropic mechanical properties. Empirical models are used for more complex fiber arrangements.
4) Strength
Optimization of Heavy Vehicle Suspension System Using CompositesIOSR Journals
A leaf spring is a simple form of spring, commonly used for the suspension in wheeled vehicles. Leaf
Springs are long and narrow plates attached to the frame of a trailer that rest above or below the trailer's axle.
There are mono leaf springs, or single-leaf springs, that consist of simply one plate of spring steel. These are
usually thick in the middle and taper out toward the end, and they don't typically offer too much strength and
suspension for towed vehicles. Drivers looking to tow heavier loads typically use multi leaf springs, which
consist of several leaf springs of varying length stacked on top of each other. The shorter the leaf spring, the
closer to the bottom it will be, giving it the same semielliptical shape a single leaf spring gets from being thicker
in the middle. The automobile industry has shown increased interest in the replacement of steel spring with
fiberglass composite leaf spring due to high strength to weight ratio. In this thesis a leaf spring used in a heavy
vehicle is designed. While designing leaf spring following four cases are considered: by changing the thickness,
changing no. of leaves, changing camber and changing span .Present used material for leaf spring is Mild Steel.
The objective of this thesis is to compare the load carrying capacity, stiffness and weight savings of composite
leaf spring with that of steel leaf spring. The design constraints are stresses and deflections. In this thesis, the
material is replaced with composites since they are less dense than steel and have good strength. The strength
validation is done using FEA software ANSYS by structural analysis. Modal analysis is also done to determine
the frequencies. Analysis is done by layer stacking method for composites by changing number of layers 3, 5, 11
and 23. The composites used are Aramid Fiber and Glass Fiber
Analysis Of Lpg Cylinder Using Composite MaterialsIOSR Journals
This paper aims is innovation of alternative materials of Liquid petroleum gas (LPG). So, the finite
element analysis of Liquefied Petroleum Gas (LPG) cylinders made of Steel and Fiber Reinforced Plastic (FRP)
composites has been carried out. Finite element analysis of composite cylinder subjected to internal pressure is
performed. Layered shell element of a versatile FE analysis package ANSYS (version 11.0) has been used to
model the shell with FRP composites.
A number of cases are considered to study the stresses and deformations due to pressure loading inside the
cylinder. First, the results of stresses and deformation for steel cylinders are compared with the analytical
solution available in literature in order to validate the model and the software. The weight savings are also
presented for steel, Glass Fiber Reinforced Plastic (GFRP) composites LPG cylinders. Variations of stresses
and deformations throughout the cylinder made of steel and GFRP are studied.
IRJET- Experimental Evaluation of Glass Fiber Reinforced Composites Subjected...IRJET Journal
This document describes an experimental study that evaluated the mechanical properties of glass fiber reinforced composites subjected to different loads. Glass fiber reinforced laminates were manufactured using the hand layup technique with ten layers of glass fiber and epoxy resin. Standard tests were conducted to determine the tensile, compression, flexural, impact, and shear properties of the laminates according to ASTM standards. The experimental results were used to characterize the strength of the glass fiber reinforced composites and how they respond to different types of loads. The study found that glass fiber reinforced composites have superior mechanical properties compared to traditional materials making them suitable for applications in industries such as aerospace, marine, and defense.
This document provides a historical overview and introduction to composite materials. It discusses:
1) The early uses of natural fiber composites throughout history for applications like bows and buildings.
2) The modern revival and increasing use of composites in aircraft and spacecraft in the late 20th century to improve structural performance.
3) Future trends toward more integrated design processes, cost reduction, and use of natural fibers to make composites more environmentally friendly.
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.
The document discusses composites materials and their properties. Composites consist of fibers and a matrix bonded together to form a strong material. The properties of composites depend on the fiber type, fiber orientation, fiber length, fiber content, and the matrix used. Natural fibers have advantages over glass fibers in terms of cost, density and sustainability, but also have limitations like moisture absorption. Proper treatment of fibers can improve adhesion between the fiber and matrix. Different manufacturing techniques like hand layup, filament winding, pultrusion are used to produce composites depending on the end application.
Mumbai University.
Mechanical Engineering
SEM III
Material Technology
Module 6
Introduction to New materials:
6.1 Composites: Basic concepts of composites, Processing of composites, advantages over metallic materials, various types of composites and their applications
6.2 Nano Materials: Introduction, Concepts, synthesis of nanomaterials, examples, applications, and Nanocomposites
6.3 An overview to Smart materials (e.g.: Rheological fluids)
IRJET-Study of Properties of Banana Fiber Reinforced with Jute FiberIRJET Journal
1. The study investigates reinforcing banana fiber with jute fiber to improve its mechanical properties for increased usage.
2. Specimens of banana and jute fiber reinforced with epoxy resin were prepared and tested for tensile strength, flexural strength, and impact resistance.
3. The tensile strength was found to increase with increased fiber thickness, while the flexural and impact strengths improved by optimizing the fiber-resin composition. Reinforcing banana fiber with jute fiber shows potential for developing stronger, more durable natural fiber composites.
Energy Release Rate for Fiber Reinforced Polymer CompositeIOSRJAP
An experimental investigation using drag-out tensile test to calculate the interfacial shear strength for different embedded lengths and radius of Kevlar -49, carbon and ultra high polyethylene fibers reinforced epoxy matrix , the energy release rate calculated by using Nairn model . The energy release rate increase as the embedded fiber length increase and also for fiber radius for perfect adhesion , for specimens with bubbles at interface which seems to reduce the fracture toughness the energy release rate be less than specimens with perfect adhesion , the thermal stress and friction forces were included in the energy release rate in Kevlar-49 and carbon reinforced epoxy the interfacial shear force due to friction part decrease while in solid ultra high polyethylene the interfacial shear force due to friction part increase.
IRJET- Fabrication and Characterization of Jute/Glass Fibre Reinforced Epoxy ...IRJET Journal
This document discusses the fabrication and characterization of jute/glass fiber reinforced epoxy hybrid composites. Various composites with different weight percentages of jute and glass fibers were created using hand layup and epoxy resin. Tensile and bending tests found that composites with 20% jute and 20% glass fiber exhibited the highest tensile strength, while composites with 28% jute and 12% glass fiber showed the highest flexural strength. The study demonstrated that hybrid composites of jute and glass fibers can improve the mechanical properties of epoxy resin.
Testing the flexural fatigue behavior of e glass epoxy laminateseSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This document analyzes LPG cylinders made of steel and carbon fiber reinforced plastics (CFRP) composites using finite element analysis. It first validates the finite element model by comparing steel cylinder results to analytical solutions. Stress and deformation variations are then studied for steel and CFRP cylinders under internal pressure loading. CFRP composites are found to provide weight savings over steel cylinders while maintaining sufficient strength for LPG storage applications.
Composite materials are composed of two or more distinct materials that produce properties different from the individual components. They have advantages like high strength to weight ratio, better fatigue and toughness properties than metals, and resistance to corrosion. Composites consist of a primary matrix phase that holds a secondary reinforcing phase like fibers, particles, or flakes. The matrix provides shape while the reinforcement improves properties. Fiber reinforced polymer composites are an important class of materials.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Seminar on composite application in aerospace enggR.K. JAIN
This document discusses a seminar on composite materials for aerospace applications. It begins with an introduction to composite materials, including their classification and advantages. Composites are made of two or more distinct phases (a matrix and dispersed phase) that provide overall superior properties compared to individual components. The document then discusses the different types of composites like particulate reinforced, fiber reinforced, and structural composites. Applications in aerospace are also presented, like usage in Boeing 777 aircraft at 12%. The document concludes that composites will play an increasingly significant role in aerospace due to properties like low weight and high strength.
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 document discusses a study on improving the impact resistance of composite laminates by embedding shape memory nitinol (NiTi) wire. Specifically:
- Specimens were prepared with layers of SiC, Kevlar fabric, and PVC foam board, with and without embedded NiTi shape memory alloy (SMA) wires.
- Low velocity impact testing was performed using a gas gun. Results showed embedding SMA wires between the SiC and PVC layers improved impact resistance, with no deformation observed, as the superelastic SMA wires dissipated impact energy uniformly.
- Without SMA wires, the composite laminates showed increasing damage from bulging to piercing under impact. The SMA wires'
This document describes Article-Level Eigenfactor (ALEF), a method for ranking and mapping scholarly articles based on their citation networks. ALEF calculates citation scores for articles, author scores based on article scores, and blends the features to generate final scores. It was developed by researchers at the University of Washington and performs well compared to other ranking methods while being simple, fast, and providing high-resolution rankings. The researchers applied ALEF to the WSDM Cup Challenge on entity ranking and achieved a score of 0.699 in Phase I.
Tractor-trailers are used all across America to transport cargo, but are not designed with fuel efficiency in mind. Therefor, there is an incentive for companies to invest in making their tractor-trailers more aerodynamic in order to save on fuel costs. I go into the testing and methodology of how my team and I decided to tackle the problem of reducing the coefficient of drag on tractor-trailers by implementing air channeling devices (ACDs). Then, I cover the results from our experiments and our ACD recommendation.
This document summarizes a student's analysis of aeroelastic divergence and flutter for a swept wing. In part 1, the student calculates the required stiffness (K) to achieve a specified divergence speed for a given wing configuration. A parametric study shows that increasing flexural rigidity (EI), torsional rigidity (GJ), or stiffness (K) increases divergence speed as expected. With K=0, the student estimates possible forward sweep angles that would achieve the required divergence speed. In part 2, the student considers flutter of the flexible wing and calculates flutter speeds for different configurations.
An introduction to the theory of aeroelasticity by y. c. fungAghilesh V
This document discusses the history and evolution of the automobile over the past century. It details some of the major technological advances that have made cars safer, more efficient and easier to drive, including the introduction of anti-lock brakes, airbags, and electronic driver assistance features. The role of computerization is also highlighted, as modern vehicles contain over 100 million lines of code to control various functions.
Structural Integrity Analysis features a collection of selected topics on structural design, safety, reliability, redundancy, strength, material science, mechanical properties of materials, composite materials, welds, finite element analysis, stress concentration, failure mechanisms and criteria. The engineering approaches focus on understanding and concept visualization rather than theoretical reasoning. The structural engineering profession plays a key role in the assurance of safety of technical systems such as metallic structures, buildings, machines, and transport. The chapter 9 explains the engineering fundamentals of composite materials and structures. Copyright 2013 Igor Kokcharov, Andrey Burov
Mechanics of Aircraft Structures solution manual C.T. Sun 2nd edDiego Fung
Designed to help students get a solid background in structural mechanics and extensively updated to help professionals get up to speed on recent advances This Second Edition of the bestselling textbook Mechanics of Aircraft Structures combines fundamentals, an overview of new materials, and rigorous analysis tools into an excellent one-semester introductory course in structural mechanics and aerospace engineering. It's also extremely useful to practicing aerospace or mechanical engineers who want to keep abreast of new materials and recent advances. Updated and expanded, this hands-on reference covers: * Introduction to elasticity of anisotropic solids, including mechanics of composite materials and laminated structures * Stress analysis of thin-walled structures with end constraints * Elastic buckling of beam-column, plates, and thin-walled bars * Fracture mechanics as a tool in studying damage tolerance and durability Designed and structured to provide a solid foundation in structural mechanics, Mechanics of Aircraft Structures, Second Edition includes more examples, more details on some of the derivations, and more sample problems to ensure that students develop a thorough understanding of the principles.
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This document provides an overview and summary of aerodynamic data for various space vehicles. It begins with a preface describing the history and development of understanding planetary motion from a geocentric to heliocentric model. It then presents aerodynamic data for several types of space vehicles, including capsules, probes, winged vehicles, and airbreathing hypersonic vehicles. The data includes configurational details, coefficients of steady and unsteady aerodynamic forces, and other technical specifications. The intent is to provide graduate students and engineers with reference aerodynamic information to support new space vehicle design projects.
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Engineering Fracture Mechanics. Engineers try to have high-strength, high ductility, high crack resistance, and faultless structures. The most reliable approach is "No cracks - no problems,"
When all is not possible, there are different methods of prevention of catastrophic failure: increase crack resistance by ductile material, by local heating; decrease SIF by placing holes on the crack path, by patching, by stiffing elements or by using composite materials. "Leak-before-break" is an effective strategy to prevent catastrophic failure of pressure vessels. It is better to allow a semi-elliptical crack to grow through the wall and to detect it by leaking than to have the dynamic start and failure of the whole vessel. There are two characteristics of the material: crack resistance for semi-elliptical crack and crack resistance for through crack.
Automatic control of aircraft and missiles 2nd ed john h. blakelockMaRwa Hamed
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This document summarizes an advanced non-linear analysis webinar presented by Alex Skavdahl. The webinar covered pre- and post-buckling behavior capabilities in FEMAP, including demonstrations on a thin-walled cylinder and box beam. It also provided information about Structures.Aero, the analysis and engineering firm that specializes in composites and lightweight structures for aerospace and other industries.
The coupling that can occur between a structure and fluid, known as aeroelasticity, can result in complex, even bizarre behavior. This is especially true when composite materials are used, as they can result in their own structurally coupled behaviors. This webinar will cover the basics involved in carrying out simple static aeroelastic as well as flutter analysis. In addition, we will also briefly explore the benefits of aeroelastic tailoring.
The document discusses aircraft landing gear, including:
1) The main functions of landing gear such as supporting the aircraft's weight and absorbing landing shocks.
2) The basic types of landing gear including fixed, retractable, and types based on arrangement like single, double, and tandem.
3) Key components of landing gear like shock struts, torque links, and the various actuators, links, and mechanisms involved.
This document provides an overview of aircraft landing gear systems. It describes the main components, including the types of landing gear arrangements (tail wheel, tandem, tricycle), construction details, alignment and retraction mechanisms, nose wheel steering, braking systems, tires, and antiskid systems. The purpose of landing gear is to support the aircraft during landing and taxiing. Retractable gear stows in the fuselage or wings to reduce drag while flying. Nose wheel steering and braking systems provide directional control on the ground. Aircraft tires must withstand high loads and provide traction for takeoff and landing. Antiskid systems help maintain braking effectiveness.
1) The document investigates the effect of stacking sequence and hybridization on the tensile and flexural properties of composites made from basalt, jute, flax, and E-glass fibers reinforced with epoxy resin.
2) It was found that stacking sequence had little effect on tensile properties but a significant effect on flexural strength and modulus, with a sandwich-like sequence performing better.
3) Hybrid composites containing E-glass and basalt fibers had the highest specific tensile strength and modulus. E-glass/basalt performed better than E-glass/jute and E-glass/flax combinations in terms of strength to weight ratio.
IRJET- Mechanical Characterization of Cissus Quadrangularis Stem/Glass Fiber ...IRJET Journal
1) The study characterized the mechanical properties of hybrid composites made from Cissus quadrangularis stem fiber (CQSF) and glass fiber reinforced unsaturated polyester.
2) Composites with 25 wt.% CQSF and 25 wt.% glass fiber exhibited significantly higher tensile, flexural, and impact strengths compared to composites with only CQSF, demonstrating that hybridizing CQSF with glass fiber enhances the mechanical properties.
3) Scanning electron microscope analysis of fracture surfaces showed good interfacial bonding between the fibers and polyester matrix in the hybrid composites.
METHOD FOR OPTIMIZATION OF COMPOSITE SANDWICH STRUCTURE USING ARTIFICIAL NEUR...IRJET Journal
This document describes a study that uses an artificial neural network to optimize the design of composite sandwich structures. Finite element analysis was used to simulate 3-point bending tests on sandwich panels with varying layer thicknesses and core properties. The FEA data was then used to train a neural network model to predict deflection and force values. The trained neural network can determine the optimal panel configuration with less computation than running additional FEA simulations. The goal is to maximize flexural strength and stiffness while minimizing weight. Key parameters like bending stiffness, energy absorption, and surface density were defined as functions of the material properties and dimensions.
Experimental Test of Stainless Steel Wire Mesh and Aluminium Alloy With Glass...IJERA Editor
At present, composite materials are mostly used in aircraft structural components, because of their excellent properties like lightweight, high strength to weight ratio, high stiffness, and corrosion resistance and less expensive. In this experimental work, the mechanical properties of laminate, this is reinforced with stainless steel wire mesh, aluminum sheet metal, perforated aluminum sheet metal and glass fibers to be laminate and investigated. The stainless steel wire mesh and perforated aluminum metal were sequentially stacked to fabricate, hybrid composites. The aluminum metal sheet is also employed with that sequence to get maximum strength and less weight. The tensile, compressive and flexure tests carried out on the hybrid composite. To investigate the mechanical properties and elastic properties of the metal matrix composite laminate of a material we are using experimental test and theoretical calculation. The experimental work consists of Tensile, compressive and flexural test. The expectation of this project results in the tensile and compressive properties of this hybrid composite it is slightly lesser than carbon fibers but it could facilitate a weight reduction compared with CFRP panels. So this hybrid laminates composite material offering significant weight savings and maximum strength over some other GFRP conventional panels.
Experimental Test of Stainless Steel Wire Mesh and Aluminium Alloy With Glass...IJERA Editor
This document summarizes an experimental study that tested the mechanical properties of a hybrid composite material made of stainless steel wire mesh, aluminum alloy sheets, glass fibers, and an epoxy matrix. Nine-ply composite laminates were fabricated using compression molding. Tensile, compressive, and flexural tests were conducted on the laminates according to standards. The results found the tensile and compressive properties to be slightly lower than carbon fibers but offered weight savings compared to conventional glass fiber reinforced panels. This hybrid composite material provides significant weight reduction and maximum strength.
The document presents a simulation and analysis of steel and composite leaf springs by varying the thickness. A composite leaf spring model is created in ANSYS and tested under a 300kg load. The deflection and stresses are compared to those of a conventional steel leaf spring. The results show that the composite leaf spring has lower deflection and stresses compared to the steel spring, and increasing the composite thickness further lowers the deflection and stress. In conclusion, the composite leaf spring can reduce weight by 75% compared to steel while maintaining sufficient strength for the application.
Effect of Nanoparticles on E-Glass Fiber Epoxy Resin CompositesIJMER
In the present work fabrication of composite material(E-Glass Fiber Epoxy Resin +
NANO CaCO3) was carried out and their tensile properties viz tensile strength, tensile
strain(%),young's modulus, energy at maximum load and brihnall hardness number were found.
Specimens of E-Glass Fiber Epoxy Resin) hybrid composites are prepared with four different
compositions of nano-calcium carbonate (CaCO3), viz., 0,3,5 and 7%.Each specimen consisting of
40%GF. The specimens are prepared by hand lay up method.. Tests are conducted on these specimens
to determine the tensile strength, tensile strain, young's modulus energy at maximum load and
hardness number at room temperature using universal testing machine and Brihnell hardness testing
machine. The influence of the nano-CaCO3 content on the mechanical properties tensile of hybrid
composites was studied. It is found that the reinforcing and toughening effects of the E-Glass epoxy
hybrid composites are increased by adding nano-CaCO3.The tensile strength, tensile strain, young’s
modulus and energy at max load of these composites increased nonlinearly with the addition of the
nano-CaCO3
This document summarizes an experimental study on the flexural fatigue behavior of carbon/epoxy angle ply laminates. Flexural fatigue tests were conducted on laminate composites with different fiber orientations: [00]4, [±450]4, [±550]4, and [00, 900]4. The tests measured the stiffness degradation of the laminates as a function of the number of load cycles applied. The results showed that stiffness reduced rapidly at first as the top and bottom layers were damaged, then the rate of reduction slowed as a "pivoting effect" limited further damage. Numerical models were able to describe the stiffness degradation curves.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Comparison between Experimental Value and Finite Element Analysis value of Gl...IRJET Journal
This document compares the experimental and finite element analysis (FEA) values for glass fiber reinforced polymer (GFRP) composite materials. Specimens with different weight percentages of E-glass fibers in epoxy resin were tested experimentally for tensile strength, bending, and impact properties. An FEA model was also created using ANSYS software. The experimental values for mechanical properties like stress and strain were generally higher than the FEA values, likely due to inhomogeneities in the real specimens from imperfect fiber-matrix mixing and air bubbles. The FEA values provided a basis for comparison to evaluate the experimental test results.
Fabrication and Analysis of Single Lap Joint Glass Fiber Reinforced Polymer C...IRJET Journal
This document summarizes research on analyzing the tensile strength of single lap joints in glass fiber reinforced polymer (GFRP) composite materials. Specifically, it looks at uni-directional and bi-directional ply composites with 10% silicon carbide additions. The composites were fabricated using hand layup and tested experimentally, numerically via finite element analysis, and analytically. Results showed that the bi-directional ply composite had a higher tensile strength than the uni-directional ply composite, making it more suitable for aircraft and automotive applications.
Composites are engineered materials made from two or more constituents with different physical or chemical
properties, which remain separate and distinct within the finished structure. A fiber is a material, which is made into
a long filament with diameter generally in the order of 10 microns. The aspect ratio of length to diameter can be
ranging from thousands to infinity in continuous fibers. Increasing worldwide environmental awareness is
encouraging scientific research into the development of cheaper, more environmentally friendly and more
sustainable construction and packing materials. For environment concern on synthetic fiber (such as glass, carbon,
ceramic gibers etc) natural fibers (such as flax, hemp, jute, kenai) etc are widely used. Industrial hemp fiber is one
of the strongest of the natural fibers available and possesses benefits such as low cost and low production energy
requirements. The primary objective of this research is to fabricate the natural fiber composites with suitable
processing/manufacturing methods and to examine the mechanical properties when subjected to Tension, Bending
and to compare & contrast the results with the available literature. In this research work, hemp fiber reinforced
Epoxy matrix composites have been developed by hand layup method with varying process parameters, such as
coupling agent(with and without compatibilizers) and different fiber percentages (10%,20% and 30% by weight).
The developed composites were then characterized by tensile test and flexural testing. Results show that the tensile
strength and flexural properties increases with the increase in fiber percentage. However after a certain percentage
the tensile strength decreases again. Compared to untreated hemp fiber, no significant changes in the tensile strength
have been observed for treated hemp fiber reinforcement. The flexural strength / modulus of the composite were
higher compared to pure epoxy for all filler/fiber loadings.
Investigation on 3-body abrasive behaviour of glass fiber and ramie fiber rei...IRJET Journal
This document summarizes an investigation into the three-body abrasive wear behavior of glass fiber and ramie fiber reinforced epoxy hybrid composites. Hybrid composites with varying proportions of glass and ramie fibers were manufactured using hand layup and tested for three-body abrasive wear under different parameters. The optimal parameters that resulted in the lowest wear rate were found to be A3 (30% ramie), B1 (580g load), and C2 (2000m sliding distance). Sliding distance was the most significant influencing factor on wear, followed by load, while fiber proportion was the least influencing. SEM analysis showed micro-plucking, micro-cutting and micro-cracks on worn surfaces. The Ra10
Hybrid polymer composites are the materials made by combining two or more
different type of fibers in a matrix. Hybrid polymer composite material offers the
designer to obtain the required properties in a controlled considerable extent by the
choice of fibers and matrix. The properties are tailored in the material by selecting
different kinds of fiber incorporated in the same resin matrix. They offer wide range of
properties that cannot be obtained with a single type of reinforcement. Due to its high
specific strengths, high specific modulus, low densities, light weight etc. based on its
applications. Presently they are playing a vital role in aerospace, defence, transport,
sport applications. Worldwide researches are keenly interested in finding out their
behavior in real life exposed to various environmental conditions, variety of loads etc.
In this paper, We fabricated carbon, e-glass and hybrid composites by using hand
layup technique in uni-directional orientation with epoxy as a matrix material and
conducted various tests such as tensile, compression on Universal Testing Machine
(UTM) and hardness. The results are validated with FEA and observed that Al-6061-
T6 which is used in manufacturing of military aircraft landing mats, truck bodies and
frames etc. has a tensile strength of about 310.25Mpa.The tensile strength of hybrid
fiber is 341Mpa which is higher than Al 6061-T6. We have compared the
experimental results with ansys results and found that the experimental values are
very close to the ansys results. But when compared within the fibers carbon fiber
exhibited more strength when compared to other fibers
COMPARATIVE AND EXPERIMENTAL INVESTIGATION OF GLASS FIBER REINFORCED WITH JUT...IRJET Journal
The document discusses an investigation into composite materials reinforced with glass fibers, jute fibers, and silicon carbide powder. Researchers looked at the mechanical properties of these composites under tensile, compression, and impact loading. They found that hand layup fabrication resulted in better performance for natural fiber reinforcement with glass fibers. Silicon carbide was shown to be an excellent material for absorbing and carrying heavy loads. The document provides details on the materials and testing methods used in the study.
Enhancing Mechanical Properties of Jute Fibre/Glass Fiber and Epoxy Combined ...IRJET Journal
This document summarizes a study that enhanced the mechanical properties of jute fiber and glass fiber composites by mixing them with epoxy resin. Four different composite laminates were fabricated using jute and glass fibers in different layer arrangements. The composites were tested for tensile strength, impact strength, hardness, and their microstructure was analyzed using SEM and EDS. The JGGJ laminate composite showed the highest tensile strength at 76.22 MPa while the GJJG laminate had the highest impact strength. SEM images revealed better bonding between jute fibers and epoxy than glass fibers. Overall, incorporating epoxy resin improved the mechanical properties of jute and glass fiber composites and made them more
IRJET- Design and Development of Natural Composite MaterialIRJET Journal
The document describes the design and development of a natural composite material made from epoxy resin reinforced with sisal fibers. Composite plates were fabricated according to ASTM standards by varying the fiber percentage and orientation. The plates were then tested for tensile and flexural strength. The objectives were to explore the potential of sisal fiber composites and evaluate how fiber percentage affects mechanical properties. Test results for composites with different fiber percentages and alignments were compared.
IRJET- Experimental Investigation of Mechanical Properties for Multilayer GFR...IRJET Journal
The document summarizes an experimental investigation of the mechanical properties of multilayer glass fiber reinforced polymer (GFRP) composites with different fiber orientations. Specifically, tensile, compressive, hardness, and impact tests were conducted on unidirectional, bidirectional, and multidirectional GFRP specimens fabricated using hand layup. The results were evaluated to determine which orientation provided the best tensile and compression strengths as well as hardness and impact resistance. Previous research on the effects of fiber orientation and other parameters on mechanical properties of FRP composites are also reviewed.
Experimental evaluation of flexural properties of polymer matrix compositesiaemedu
This document discusses an experimental evaluation of the flexural properties of polymer matrix composites reinforced with glass and carbon fibers. Three-point bending tests were conducted on laminate beams fabricated with bi-woven glass and carbon fibers in epoxy resin. The test results showed that carbon fiber composites had higher flexural strength and stiffness compared to glass fiber composites. Additionally, increasing the laminate thickness from 2mm to 3mm improved the flexural properties. The findings from the experimental tests agreed with theoretical predictions about the superior mechanical properties of carbon fibers relative to other fiber types.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
1. University of Miami
Master’s Project (MAE 751) – Micromechanical
Analysis of Hybrid Composites
Dr. Karkainnen
Omar Kashkash
12/14/2015
2. Abstract
A micromechanical analysis has been done for a hybrid composite model with
carbon and dyneema SK-60 fibers for military applications. The finite element
analysis was done using ABAQUS software to obtain stiffness and strength
properties. Different fiber combinations were studied for comparison.
Introduction
Hybrid composites have increased in popularity due to their unique features
that can be used to meet various design requirements in a more economical way
than conventional composites. For example, expensive fibers such as graphite and
boron can partially be replaced by less expensive fibers such as glass and Kevlar.
Hybrid composites can contain several different fiber types in a single matrix,
however, it has been found that a combination of only two types of fibers would
be most beneficial. Some of the specific advantages of hybrid composites over
conventional composites include balanced strength and stiffness, balanced
bending and membrane mechanical properties, balanced thermal distortion
stability, reduced weight and/or cost, improved fatigue resistance, reduced notch
sensitivity, improved fracture toughness and/or crack arresting properties, and
improved impact resistance.
A computational model is created using ABAQUS software that can easily be
modified to model hybrid composites of different volume fractions of
constituents. This saves the designer valuable time and resource as opposed to
experimental techniques that require fabrication of various composites with
various fibers, their volume fractions and matrix properties in hybrid composites
which are time consuming and cost prohibitive.
In this paper, a computational model is presented in which finite element based
micromechanics is used to obtain results of strength and stiffness properties.
Direct Micromechanics Method (DMM) is used for predicting strength, which is
based on first element failure method; although conservative, it provides a good
estimate for failure initiation [1 & 2].
3. Carbon Dyneema Hybrid Composites
Dyneema fibers are made from ultrahigh molecular weight polyethylene
(UHMWPE). In the process called gel spinning the very long molecules are
dissolved in a volatile solvent and spun through a spinnerette. In the solution the
molecules get disentangled and remain so after cooling in gel-like filaments (See
Figure 1). As the fiber is drawn, a very high level of macromolecular orientation is
attained and a high fiber with a very high tenacity and modulus is obtained (See
Figure 2). This fiber is now available as Dyneema SK60. It is characterised by a
parallel orientation greater than 95% and a high level of crystallinity (up to 85%).
This gives Dyneema SK60 its specific properties. A comparison with other fibers is
given below (See Table 1). On a weight-for-weight basis Dyneema is the strongest
fiber on the market. Its tensile strength is 2.7 GPa, which combined with a density
less than 1, gives a tenacity, or specific strength, of 30 g/den. Modulus is also very
high: 87 GPa and on a specific basis 1.000 g/den. Even higher values may be
expected in the future as research continues. A comparison of Dyneema with
other high performance fibrers is given below (See Figures 3 & 4). Figure 3 gives
specific strength versus specific modulus while Figure 4 is the stress/strain
diagram. Dyneema SK60 is advantageous in composites where weight saving is
important. Dyneema composites can be strong and stiff in tension and that light
weight composites can be made using this fiber. However, compression and shear
modulus will often be limiting when using only Dyneema fibers in a composite. So,
in general, hybrids will be used in which the strong points of the Dyneema fiber in
the construction will lower the weight and give high stiffness and high tensile
strength with a good dimensional stability. Composites made from carbon fibers
are extremely strong, stiff and lightweight structural materials. Therefore, such
composites are very suitable for application as aircraft skin material. However,
sheets from carbon composite skins are somewhat sensitive to the out of plane
loads caused by impact. Hybridizing with gel-spun polyethylene fibers is a well-
known way to improve the resistance against impact [3, 4, and 5]
4. Figure.1 Dyneema Gel Spinning Process
Figure.2 Macromolecular orientation of Dyneema SK60
5.
6. The low compressive strength of Dyneema SK60 makes it unsuitable for structural
aerospace composites as a sole fiber ingredient. Compression resistant fibers like
glass or carbon are needed for such applications. However, Dyneema® fibers are
excellent for armor applications [6]. This is due to the combination of high tensile
strength, low density and intrinsic fiber toughness. This fiber toughness is
illustrated below (See Figures 5 & 6). Figure 5 shows a knotted filament. The
curvatures in the knot and the transverse deformation are impossible for other
high strength fiber types like glass, carbon or aramid fibers. Figure 6 shows
filaments that are tensioned over the edge of a sharp razor blade. Again, a sharp
curvature and extensive transverse deformation occur, allowing pressure re-
distribution over a larger distance along the blade edge. Thus the excellent cutting
resistance is explained. Both pictures illustrate the damage tolerance of
Dyneema® on micro-scale. Hybridization with a carbon fiber composite may add
damage tolerance to the composite on macro scale.
7. Results from [7] show that hybridizing the carbon composite with Dyneema®
fibers improves the resistance to impact considerably. The impact resistance
increases with increasing amount of Dyneema® fibers. Figure 7 shows a Scanning
Electron Microscope (SEM) picture indicating deformed, but unbroken Dyneema®
fibers together with broken carbon fibers, thus illustrating the contribution of the
damage tolerant Dyneema® fibers to the impact resistance of the hybrid
composite
8. Methodology
After a plain weave hybrid composite model has been created (See Figures 8 and
9), the following steps were done to run 6 unit strain cases in ABAQUS software
[8]:
Figure 8. Location and definition in RVE
9. Figure 9. Warp and Weft yarns
- In property module, define material properties of fiber, matrix, and
interface (See Table 2). Also, define local material coordinates to easily
interpret longitudinal stresses for both Carbon (Warp) and Dyneema (Weft)
fibers by setting the primary axis 1 along the direction of fibers (See Figure
10).
Table.2 Mechanical Properties of UD laminates (approx. 55% fiber in epoxy
laminates)
Engineering constants Carbon IM7 fiber Dyneema SK60 fiber
E1 (GPa) 136 46.6
E2 (GPa) 11.5 3.6
E3 (GPa) 11.5 3.6
V12 0.31 0.32
V13 0.31 0.32
V23 0.35 0.35
G12 (GPa) 5.19 1.1
G13 (GPa) 5.19 1.1
G23 (GPa) 4.26 1.374045802
Density of fibers 0.002 0.002
Matrix data
10. Young’s modulus (GPa) 3.5
Poisson’s ratio 0.35
Density 0.00125
Interface data
Density 0.00125
Young’s modulus (GPa) 3.5
Poisons ratio 0.35
Figure.10 Local Material Coordinates of fibers
- In mesh module, 3-D continuum elements can be hexahedral (bricks),
wedges, or tetrahedral. Whenever possible, hexahedral elements or
second- order tetrahedral elements should be used in ABAQUS (See Figures
11, 12, and 13). First-order tetrahedral (C3D4) have a simple, constant-
strain formulation, and very fine meshes are required for an accurate
solution.
11. Figure.11 Meshed yarns
Figure.12 Meshed Interface
Figure.13 Meshed Representative Volume Element (RVE)
- In load module, boundary conditions are defined for each unit strain case
with unit normal strain cases having four boundary conditions and unit
12. shear strain cases having three boundary conditions (See Figures 14 & 15,
Table 3, and Appendices).
Figure.14 Definition of each side in RVE
Figure.15 Degrees of freedom
13. Table.3 Boundary conditions for both unit normal strain and unit shear
strain cases
Unit normal
strain cases
front back right left top bottom
Case1 U*1=6 U1=0 U3=0 U3=0 U2=0 U2=0
Case2 U1=0 U1=0 U3=0 U3=0 U2=1.38 U2=0
Case3 U1=0 U1=0 U3=0 U3=6 U2=0 U2=0
Unit shear strain
cases
Case1 U1=0 ;
U2=1.38
U1=0 ;
U2=0
U3=0 U3=0
Case2 U1=0 U1=0 U3=0 ;
U2=0
U3=0 ;
U2=1.38
Case3 U1=0 ;
U3=6
U1=0 ;
U3=0
U2=0 U2=0
*Boundary conditions are in units of mm and only displacement degrees of
freedom were used in the simulation
- In job module, a job is made for each unit strain case.
- In visualization module, a representative volume element (RVE) analysis is
done to obtain forces at every node on a surface. The summation of these
forces divided by the area of the surface outputs stress on that surface. This
analysis is put into an EXCEL file to invert stiffness [C] matrix into
compliance [S] matrix from which elastic constants(stiffness properties) can
be found [9, 10, 11, 12, & 13].
Results
A comparison of stress strain graphs highlighting the first fiber to fail
longitudinally in each unit strain case while highlighting matrix failure if it occurs
before it. For both RVE’s, all the elements experience failure due to the full unit
strain case applied except for a very few that will be noted below. The five modes
of failure are fiber (longitudinal, transverse, and shear) and matrix (normal and
shear). Highlighting the first longitudinal failure for the fiber in either warp (x dir.)
or weft (z dir.) doesn’t represent composite failure because the other fiber have
14. not failed longitudinally yet. This method is called the first element failure
method which is conservative and important as a first step. Note in the graphs
that a single asterisk is for matrix failure and a double asterisk is for first
longitudinal fiber failure.
0.00749255, 107.8706198
CF, x dir. Longitudinal
Failure **
0.001659329,
23.88945026
Epoxy Normal Failure*
0.006382979,
91.89606593
Epoxy Shear
Failure*
-500
0
500
1000
1500
2000
2500
3000
3500
4000
4500
-0.05 0 0.05 0.1 0.15 0.2 0.25 0.3
Stress(σfcellandτfcell(Mpa))
Failure Strain in the Material (ϵf and γf)
Hybrid Unit Strain Case 1:ϵx=1
0.007398066,
118.5163775
CF, x dir. Longitudinal
Failure**
0.00163606,
26.20953984
Epoxy Normal Failure*
0.006435986,
103.1039359
Epoxy Shear Failure*
-1000
-500
0
500
1000
1500
2000
2500
3000
3500
4000
4500
-0.05 0 0.05 0.1 0.15 0.2 0.25 0.3
Stress(σfcellandτfcell(Mpa))
Failure Strain in the Material (ϵf and γf)
Unit Strain Case 1:ϵx=1
15. 0.281060364,
1326.310722
CF, x dir. Longitudinal
0.003257979,
15.37424933
Epoxy Normal Failure*
0.022169249,
104.6156504
Epoxy Shear
-400
-200
0
200
400
600
800
1000
1200
1400
1600
1800
-0.1 -0.05 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
Stress(σfcellandτfcell(Mpa))
Failure Strain in the Material (ϵf and γf)
HybridUnit Strain Case 2:ϵy=1
0.000325745, 1.887087512
CF, x dir. Longitudinal failure with
CF, x&z dir. Shear failure occuring before it
-500
0
500
1000
1500
2000
2500
-0.05 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35
Stress(σfcellandτfcell(Mpa))
Failure Strain in the Material (ϵf and γf)
Unit Strain Case 2:ϵy=1
0.016589003,
146.1145424
DF, z dir. Longitudinal
Failure**
0.00251411,
22.14406781
Epoxy Normal Failure*
0.010334482,
91.02524542
Epoxy Shear Failure*
-500
0
500
1000
1500
2000
-0.05 0 0.05 0.1 0.15 0.2 0.25
Stress(σfcellandτfcell(Mpa))
Failure Strain in the Material (ϵf and γf)
Hybrid Unit Strain Case 3:ϵz=1
16. 0.007398066,
118.5163775
CF, x dir. Longitudinal
Failure**
0.00163606,
26.20953984
Epoxy Normal Failure*
0.006435986,
103.1039359
Epoxy Shear Failure*
-1000
-500
0
500
1000
1500
2000
2500
3000
3500
4000
4500
-0.05 0 0.05 0.1 0.15 0.2 0.25 0.3
Stress(σfcellandτfcell(Mpa))
Failure Strain in the Material (ϵf and γf)
Unit Strain Case 3:ϵz=1
0.215422277,
14.62795312
CF, x dir. Longitudinal
Failure**
0.044343891,
3.011110897
Epoxy Normal Failure*
0.209176788,
14.20386182
Epoxy Shear Failure*
0
2
4
6
8
10
12
14
16
0 0.05 0.1 0.15 0.2 0.25
Stress(σfcellandτfcell(Mpa))
Failure Strain in the Material (ϵf and γf)
Hybrid Unit Strain Case 4:γxy=1
0.209498869,
1153.121065
CF, x dir. Longitudinal
Failure**
and CF, z dir.
Longitudinal doesn't
fail
0.043324492,
238.4661268
Epoxy Normal Failure*
0.203323131,
1119.128643
Epoxy Shear Failure*
-200
0
200
400
600
800
1000
1200
1400
-0.05 0 0.05 0.1 0.15 0.2 0.25
Stress(σfcellandτfcell(Mpa))
Failure Strain in the Material (ϵf and γf)
Unit Strain Case 4:γxy=1
17. 0.579489962,
31.95328161
DF, z dir. Longitudinal
Failure**
0.050107373,
2.762938279
Epoxy Normal Failure*
0.289629399,
15.97026757
Epoxy Shear Failure*
-5
0
5
10
15
20
25
30
35
-0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
Stress(σfcellandτfcell(Mpa))
Failure Strain in the Material (ϵf and γf)
Hybrid Unit Strain Case 5:γyz=1
0.209498869, 1153.121065
CF, x dir. Longitudinal
Failure**
and CF, z dir. Longitudinal
doesn't fail
0.043324492,
238.4661268
Epoxy Normal Failure*
0.203323131,
1119.128643
Epoxy Shear Failure*
-200
0
200
400
600
800
1000
1200
1400
-0.05 0 0.05 0.1 0.15 0.2 0.25
Stress(σfcellandτfcell(Mpa))
Failure Strain in the Material (ϵf and γf)
Unit Strain Case 5:γyz=1
18. Table.4 Allowable Composite and Matrix Strength Properties
Fibers -> Dyneema SK60 Carbon IM7
Longitudinal Stress 1068 1760
Transverse Stress 7.2 81.3
Shear Stress 15.9 0.48
Matrix -> Epoxy
Longitudinal Stress 49
Shear Stress 93
*units are in MPa
This table is used for comparing the stress values obtained from Abaqus as
a result of each of the unit strain cases with those from the literature and
0.031333452,
41.67619244
CF, x dir. Longitudinal
Failure
0.006344685,
8.438977635
Epoxy Normal Failure*
0.023111332,
30.74006399
Epoxy Shear Failure*
-100
0
100
200
300
400
500
600
-0.05 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45
Stress(σfcellandτfcell(Mpa))
Failure Strain in the Material (ϵf and γf)
Hybrid Unit Strain Case 6:γzx=1
0.027056111,
1.965828857
CF, x dir. Longitudinal
Failure**
0.005675237 ,
0.412348458
Epoxy Normal Failure*
0.017247774,
1.253179853
Epoxy Shear Failure*
-5
0
5
10
15
20
25
30
-0.05 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
Stress(σfcellandτfcell(Mpa))
Failure Strain in the Material (ϵf and γf)
Unit Strain Case 6:γzx=1
19. plotting the stress strain graphs.
The uniaxial failure points for the warp(x dir.) and weft (z dir.) are defined
as the longitudinal far field stress that causes fiber failure in the warp from
unit strain case 1 and weft from unit strain case 3 for both RVE’s [14 & 15].
Table.5 Stiffness properties for both RVE’s
Engineering Constants C,C C,Dyneema
Ex (GPa) 16.01991262 14.39705033
Ey (GPa) 5.793144219 4.718953262
Ez (GPa) 16.02313277 8.807915952
Vxy 0.455247679 0.455636536
Vyx 0.455247709 0.149344901
0, 146.1145424
Hybrid
-107.8706198, 0
Hybrid
0, 118.5163775
Non-hybrid
118.5163775, 0
Non-hybrid
-200
-150
-100
-50
0
50
100
150
200
-150 -100 -50 0 50 100 150
WarpMPa
Weft MPa
Uniaxial Failure Points
Hybrid
Non-hybrid
20. Vyz 0.164650914 0.235034449
Vzy 0.164650774 0.438690752
Vzx 0.109435236 0.100312805
Vxz 0.109413166 0.163966889
Gxy (GPa) 5.504187539 0.067903623
Gyz (GPa) 0.072619677 0.055140354
Gxz (GPa) 0.072657481 1.33008621
Discussion
From table.5 and the stress strain graphs the first unit strain
comparison between RVE’s has values of Ex= 16 and 14.4 GPa’s, for the
non-hybrid and hybrid, respectively. The hybrid experiences first
longitudinal fiber failure perhaps because the dyneema allows the
carbon fibers to strain faster and thus fail faster due to the RVE plain
weave geometry.
Conclusion
In general, the amount of Dyneema® fibers will not be higher than 50%, usually
even lower. Very high amounts of Dyneema® fibers are reserved for composites
with armor functionality only. Such composites utilize the tensile strength and
damage resistance of Dyneema® fibers to a full extent, but exhibit hardly the
balance of properties of structural materials. Combination with carbon fibers
provides more balanced structural properties.
Composites allow trading of property directions by choosing relative amounts of
fibers in different orientations. The amounts of choices are increased, considering
that replacing carbon fibers by Dyneema® fibers allow trading of compression
strength and ILSS against impact resistance. Hybrid composites with carbon fibers
and Dyneema® fibers show considerably improved impact resistance over
composites with carbon fibers only .
21. Moreover, application of carbon Dyneema® hybrid composites can be considered
as an improvement option over pure carbon composites if the situations below
apply:
1. The structure is critical on impact resistance
2. The structure is mainly designed for tension load, and/or
3. The structure is a thin skin
Consequently, it is concluded that Carbon Dyneema® hybrid composites may be
attractive for structures where impact resistance is the limiting load case and
flexural resistance is important as well [16, 17, & 18].
References
[1] Tsai SW, Hahn HT. Introduction to composite materials. Lancaster (PA):
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[2] S. Banerjee and B. V. Sankar. “Mechanical Properties of Hybrid Composites
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Appendices
Unit Normal Strain cases
Case 1:𝜀 𝑥 = 1