For brittle fracture behaviour of carbon fibre reinforced plastics (CFRP) under compression, several approaches exist, which describe different mechanisms during failure, especially at stress intensifications. The failure process is not only initiated by the buckling fibres, but a shear driven fibre compressive failure beneficiaries or initiates the formation of fibres into a kink-band. Startin...

The probabilistic analysis takes into consideration an effect of scatter in elastic and strength properties of composite beam, and velocity of impactor. The damage model is implemented in the FE (finite element) code by a VUMAT (user-defined subroutine). The inter ply failure is modeled using cohesive surfaces between the plies. Dynamic response is obtained using explicit time domain integratio...

A finite element model based on the layerwise theory is developed for the analysis of transverse cracking in cross-ply laminated beams. The numerical model is developed using the layerwise theory of Reddy, and the von Kármán type nonlinear strain field is adopted to accommodate the moderately large rotations of the beam. The finite element beam model is verified by comparing the present numeric...

Introduction Transverse matrix cracking in cross-ply gr/ep laminates was studied with advanced acoustic emission (AE) techniques. The primary goal of this research was to measure the load required to initiate the first transverse matrix crack in cross-ply laminates of different thicknesses. Other methods had been previously used for these measurements including penetrant enhanced radiography, o...

Optimum laminate configuration for minimum weight of filament–wound laminated conical shells subject to buckling load constraint is investigated. In the case of a laminated conical shell the thickness and the ply orientation (the design variables) are functions of the shell coordinates, influencing both the buckling load and its weight. These effects complicate the optimization problem consider...

At this stage a substantial body of literature exists for shape optimization involving isotropic materials. The reader is referred to the articles of Haug [1] and Haftka and Grandhi [2] for overviews of the material. One approach to the problem is analytical. Calculus of variation techniques are employed to derive explicit optimality conditions. Choi and Haug [3], Dems and Mroz [4], and Banichu...

BACKGROUND Biaxial (BX) and triaxial (TX) composite laminates with ±45° angled plies have been widely used in wind turbine blades. As the scale of blades increases, BX and TX laminates with shallow-angled plies (i.e. off-axis ply angle <45°) might be utilized for reducing mass and/or improving performance. The compressive properties of shallow-angled BX and TX laminates are critical considering...

The present study investigates torsional and compressive loading of a paperboard package. Finite element (FE) analyses simulating the tests were performed to improve understanding stresses deformations in during loading. A simple experimental characterization necessary material properties could be represent multi-ply as single-ply structure. results from model compared with laminate model, diff...