The aim of this book is to characterize the interfacial integrity and its implication on mechanical behaviour of FRP composites.Recently an active area of investigation related to this work is being explored by Temperature Modulated differential scanning calorimetry (TMDSC) and Fourier Transform Infrared Spectroscopy (FTIR-Imaging) techniques to pin down the causes for a reduce stress transmissibility at the interface. Surface treated glass fiber, carbon fiber and epoxy matrix were used to fabricate micro-composite. Change in FTIR spectra shows alternation and deviation of stoichiometry. The analysis of these suggests that there is a variation in the chemical structure of the matrix from the fiber to the polymer bulk due to different conversions arising from a gradient in the initial composition. And in TMDSC the focus has been emphasized on Tg value which increases when hygrothermal treatment duration is less because of formation of double hydrogen bond and replacing the covalent bond. The increase in Tg value may often lead to the enhanced mechanical properties like interlaminar shear strength.
The book is designed to serve as a textbook for students of mechanical and metallurgical engineering. The book generally provides the methods of development of Polymer composites (epoxy filled)and evaluation of the various mechanical properties of developed composite. The book describes the statistical techniques, probability plots with the help of Matlab Software. Book also describes the use of Fly Ash (waste product from power plants) in the developed composites.
An experimental investigation is carried out to examine the use of multi-walled carbon nanotubes (MWCNTs) in producing a new generation of fiber reinforced polymer (FRP) composites. First, the nanotubes are used to produce epoxy nanocomposites. The experiments showed significant improvements in flexure properties of the MWCNT-epoxy nanocomposites when functionalized nanotubes are used. Second, MWCNT-epoxy nanocomposites were used to fabricate woven carbon fabric composites in order to examine their static, impact, and creep behaviors. The MWCNTs improved the off-axis tension, off-axis flexure, FRP lap shear joint responses. In addition, they reduced the creep of epoxy adhesives at FRP-concrete interface, enhanced the fracture toughness, and altered the impact resistance significantly. In general, the MWCNTs are found to affect the performance of the FRP composites when matrix failure governs the behavior. The improvement in the mechanical response with the addition of low contents of MWCNTs would benefit many industrial and military applications such as strengthening structures using FRP composites, composite pipelines, aircrafts, and armored vehicles.
Nowadays, natural fiber reinforced polymer composites are increasingly being used for varieties of engineering applications due to their many advantages. Among natural fibers, bamboo has been widely used for many such applications due to its availability. Since these composites are finding wide applications in highly dusty environment which are subjected to solid particle erosion, a study of their erosion characteristics are of vital importance. Generally solid particle erosion, a typical wear mode leads to material loss due to repeated impact of solid particles. For a composite material, its mechanical behavior and surface damage by solid particle erosion depends on many factors. Attempts have been made in this study to explore the potential utilization of bamboo fiber in polymer matrix composites. Therefore, the present research is focused on the mechanical and erosion wear behavior of short bamboo fiber reinforced composites filled with Alumina (Al2O3) particulate. It further outlines a methodology based on Taguchi’s experimental design approach to make a parametric analysis of erosion characteristics. Finally, the morphology of eroded surfaces is examined using SEM.
A collection of 23 papers from The American Ceramic Society's 40th International Conference on Advanced Ceramics and Composites, held in Daytona Beach, Florida, January 24-29, 2016. This issue includes papers presented in Symposium 1 - Mechanical Behavior and Performance of Ceramics and Composites.
The present work reports the synthesis, fabrication and characterization of hydroxyapatite (HAp) based polyethylene bio-composites as an artificial bone implant material. The main problem with the metallic bone implants is the stress shielding and bone regeneration, which may be overcome by introducing polymer based light weight bone implants. HAp was synthesized by wet chemical precipitation technique and mixed with high density polyethylene (HDPE) and high molecular high density polyethylene (HMHDPE) using micro-compounder and twin screw extruder. Mocro-injection molding and compression molding processes were used to prepare the samples. Testing of different mechanical properties like tensile, compressive, flexural, impact and two body abrasion wear has been carried out. The experimental results showed a sustainable mechanical behavior. An artificial neural network (ANN) and a fuzzy logic (FL) model have been presented, for the prediction of two-body abrasion wear amount of the fabricated bio-composites. It was found that both the fuzzy and ANN model are able to predict the abrasion wear rate with a very high degree of accuracy.
This theoretical work has the purpose to thoroughly investigate the problems of shear-horizontal (SH) interfacial acoustic wave propagation guided by the common interface between two dissimilar piezoelectromagnetic hexagonal half-spaces of class 6 mm. At the interface, the mechanical, electrical, and magnetic boundary conditions can support the interfacial SH-wave propagation. The equality of the mechanical displacements and the normal components of the stress tensor (mechanically free interface) were used as the mechanical boundary conditions. The electrical and magnetic boundary conditions can include the electrically closed or electrically open interface, magnetically closed or magnetically open interface, and the others. As a result, twenty two new interfacial SH-waves can propagate in such two-layer structures. Their propagation speeds can be evaluated using the obtained explicit forms and the corresponding existence conditions. Some sample calculations were performed for PZT–Terfenol-D and BaTiO3–CoFe2O4 composites. The results can be useful for complete understanding of wave processes in two-phase laminated composites in acoustoelectronics and optoelectronics.
-Provide a better understanding of Aluminum and its role in industry. -A simplified explanation of the most common mechanical and material testing in industry. -Concentrate on fatigue as one of the main reasons behind parts failure. -Ideal for undergraduate students in different engineering disciplines. -Encourage the industry field and private sector community to support and cooperate with undergraduate students and academic institutions.
Metal Matrix ceramic-reinforced composites are rapidly becoming strong candidates as structural materials for many high temperatures and aerospace applications. Metal matrix composites combine the ductile properties of the matrix with a brittle phase of the reinforcement, leading to high stiffness and strength with a reduction in structural weight. The satisfactory performance of metal matrix composites depends critically on their integrity, the heart of which is the quality of the matrix-reinforcement interface. The nature of the interface depends on the processing of the metal matrix composite component. The Al/SiCp composites studied, processed in specific thermo-mechanical conditions in order to attain higher values of interfacial fracture strength, due to precipitation hardening and segregation mechanisms, also exhibited enhanced bulk mechanical and fracture resistant properties. An analytical model to predict the interfacial fracture strength in the presence of material segregation was also developed during this research effort.
Assessment, Treatment, and Prevention of Suicidal Behavior
In this book, coir fiber was chemically treated with acrylonitrile to improve the physical and mechanical properties of the coir-PP composites. Physical and mechanical properties of the composites prepared from treated coir were found better than those of untreated ones. The tensile strength, tensile modulus, flexural strength, flexural modulus, and hardness of the chemically treated coir fiber reinforced composites were higher than those of the raw ones. Treated coir-PP composites were found to absorb less amount of water than the untreated ones. To understand why the mechanical properties of composites prepared under different conditions of coir were different, surface morphologies of the tensile fractured surfaces of the specimens were recorded using scanning electron microscopy (SEM). The SEM images clearly revealed that there were fewer fiber agglomerations, micro-voids, and fiber pull out traces for treated coir-PP composite than in the untreated one, indicating that better distribution of the fiber into the matrix as well as stronger fiber matrix interfacial adhesion occurred upon treatment of coir.
Mechanical Properties and Performance of Engineering Ceramics and Composites
Mechanical Properties and Performance of Engineering Ceramics and Composites IV
Rice husk is an agricultural byproduct available in very large quantities throughout the world. Rice husk, which essentially protects the rice grain during growth, contains approximately 90 to 95% silica and the rest being minor oxides. In recent years considerable efforts have been made to utilize the silicon rich rice husk ash for making useful products. Recently efforts are being made to find value addition to these byproducts by using them as secondary resource materials. Damping capacity is a manifestation of anelastic behavior, i.e. a time-dependent response to an applied load. Materials with high damping capacity are very desirable to suppress mechanical vibration and transition of waves, thus decreasing noise and maintaining the stability of structural systems. Metal matrix composites, mostly of aluminum are sensitive to vibration because of their light weight. With the increasing applications of metal matrix composites, the requirement for high damping capacity of the materials is becoming more and more important for the advanced structures. Present work is an experimental investigation of the damping behavior of rice husk ash reinforced metal matrix composites.
Fiber Reinforced Polymer (FRP) composites have emerged as an alternative to traditional materials for strengthening/rehabilitation of existing structures. The light weight of the material, high-strength to weight ratio, corrosion resistance, and high efficiency of construction are among many of the advantages which encourage civil engineers to use this material. FRP composites have been used in the retrofit of bridge columns due to insufficient capacity or displacement ductility. It is a well-established fact that FRP jackets can provide effective lateral confinement to concrete columns that can substantially enhance their compressive strength and ultimate axial strain. One of the most important problems civil engineers are concerned with is the stress-strain relationship of FRP-confined concrete.