SUMMARY Theoretical analyses are made of the influence of the following features on the longitudinal shear and transverse tensile moduli of unidirectional fibre reinforced composites: (i) random variations in positioning of individual fibres, (ii) overall variations leading to fibre bunching, (iii) overall variations leading to interspersed matrix layers, (iv) localised variations resulting in ...

In present work 2D FE (finite element) analysis of deformation and damage evolution site in fiber reinforced composites are carried out. The fiber cracking point and stresses is simulated in the fibers/matrix interface, using the ANSYS FE software at varying volume fractions. The effect of matrix cracks and the interface strength on the fiber failure is investigated. Multi-fibre model were used...

This paper presents an experimental study on the development of polymer bio-composites. The powdered coconut shell, walnut shells and Rice husk are used as reinforcements with bio epoxy resin to form hybrid composite specimens. The fiber compositions in each specimen are 1:1 while the resin and hardener composition 10:1 respectively. The fabricated composites were tested as per ASTM standards t...

A structural health monitoring (SHM) study of biaxial glass fibre-reinforced epoxy matrix composites under a constant, high strain uniaxial fatigue loading is performed using fibre Bragg grating (FBG) optical sensors embedded in composites at various locations to monitor the evolution of local strains, thereby understanding the damage mechanisms. Concurrently, the temperature changes of the sam...

This paper investigates the hygrothermal effects on the failure mechanisms in bending of carbon fibre reinforced polymer (CFRP) composites. Accelerated diffusion testing was carried out by immersion at 50°C constant temperature and 70 bar hydrostatic pressure to study the effects of fresh or sea water diffusion into pre-preg CFRP laminates. Consequently the composite laminates were tested in be...

The role of particle-toughening for increasing impact damage resistance in carbon fibre reinforced polymer (CFRP) composites was investigated. Five carbon fibre reinforced systems consisting of four particle-toughened matrices and one system containing no toughening particles were subjected to low velocity impacts ranging from 25 J to 50 J to establish the impact damage resistance of each mater...

The material properties of greatest importance in microwave processing of a dielectric are the complex relative permittivity epsilon = epsilon'-jepsilon", and the loss tangent, tan delta = epsilon"/epsilon'. This paper describes two convenient laboratory based methods to obtain epsilon', epsilon" and hence tan delta of fibre-reinforced thermoplastic (FRTP) composites. One method employs a micro...

This paper presents the results of an initial investigation into the potential for monitoring water absorption and chemical degradation in epoxy matrix composites using evanescent wave spectroscopy. While conventional silica glasses have too low a refractive index and too short an IR transmission window to be useful as unclad sensing elements in most resin systems, chalcogenide glasses offer su...