Development of a specialised finite element for the analysis of composite structures with ply drop-off

A global-local approach for the analysis of tapered laminated composites is presented. The method is considerably more economical than existing techniques. A new drop-off element that is degenerated from a 2-dimensional (2-D) drop-off element is introduced to carry out the global analysis. The drop-off element accommodates the termination of plies within the element and therefore, the size of the stiffness matrix reduces. Al the vicinity of the drop-off where the stress concentration is high a local analysis with a refined mesh is performed with the results of the global analysis. Since a fine mesh is to be adopted only near the drop-off there is substantial economy in the computational effort and time as compared to the conventional analysis models. The present method has been validated extensively against published results. A discussion of the stress/strain distribution at different locations has been presented. (C) 1999 Elsevier Science Ltd. All rights reserved.