A three-dimensional spectral element method SEM was developed for analysis of Lamb wave propagation in composite laminates containing a delamination. SEM is more efficient in simulating wave propagation in structures than conventional finite element method FEM because of its unique diagonal form of the mass matrix. Three types of composite laminates, namely, unidirectional-ply laminates, cross-...

This paper investigates the scattering characteristics of the fundamental anti-symmetric (A(0)) Lamb wave at through holes in composite laminates. Three-dimensional (3D) finite element (FE) simulations and experimental measurements are used to study the physical phenomenon. Unidirectional, bidirectional, and quasi-isotropic composite laminates are considered in the study. The influence of diffe...

the residual stresses in composite laminates depend on several factors including the conditions of fabricating process, property of materials, direction and lay-ups of the layers. however the thermo-elastic behavior of composite is one of the most important parameters affecting the magnitude of residual stresses. the elastic properties and residual stresses do not remain constant under cyclic t...

Mechanical properties of the fibers extracted from the areca are determined and compared with the other known natural fiber coir. Further these Areca fibers were chemically treated and the effect of this treatment on fiber strength is studied. Areca fiber composite laminates were prepared with randomly distributed fibers in Maize stalk fine fiber and Phenol Formaldehyde. Composite laminates wer...

This research paper compares the thermal conductivity and thermal expansion coefficients of glass fiber reinforced epoxy composite laminates (GFRP laminates) made using the Hand layup technique. The composite laminates were fabricated by filling with varying concentrations of fly ash, stone powder, aluminium oxide (Al2O3), magnesium hydroxide (Mg (OH)2), Silicon carbide particles(SiC) and hemat...

Impact tests were carried out on composite laminates and composite scarf repairs, while both were subjected to in-plane loading with tensile pre-strain levels up to 5000 microstrain. The results show that pre-straining of the composite laminates has no noticeable influence on the size of the delamination area for the given impact energy of 8 J, which represents a typical barely-visible impact o...

The purpose of this study is to review many of the available guidelines for Polymer composite materials. Guide lines for failure mode, laminates orientation, winding angle, water absorption, as they strongly influence the mechanical properties of composite materials. The present review is focused on composite laminates made of glass, carbon, graphite, hybrid and natural fiber composites, since ...

In this paper, the problem of tensile strength prediction of composite laminates containing artificially implanted holes is confronted. An approach based on the integration of acoustic emission and load data through neural network is presented. The obtained results show that neural networks can be a useful tool in the monitoring of fracture behavior of composite laminates through acoustic emiss...

A finite element (FE) model is developed to investigate mode I delamination toughness of z-pin reinforced composite laminates. The z-pin pullout process is simulated by the deformation of a set of non-linear springs. A critical crack opening displacement (COD) criterion is used to simulate crack growth in a double-cantilever-beam (DCB) made of z-pinned laminates. The toughness of the structure ...

In this research, residual strength and stress concentration factor of laminated composites with a circular open hole are studied analytically, numerically and experimentally. The numerical study was carried out using the finite element method. Moreover an analytical study was carried out with developing of point stress criterion. Mechanical testing was performed to determine the un-notched ten...