Experimental and Numerical Study of Composite T-Joints

Abstract

The present paper deals with experimental and nonlinear finite element analysis of sandwich T-joints which are formed by two panels connected by lap joints. Such joints are for instance commonly used in high-speed marine vehicles, and the joints considered herein are typical for such structures. This study is concerned with T-joints subjected to tension (pull-out) force and the behaviour up to ultimate failure. The behaviour of such sandwich joints is very complex, since it involves several types of materials such as GRP, glue filler as well as foam material, and a geometry with potential high stress concentrations. Also, nonlinear material and geometrical effects may influence the ultimate behaviour. In this study experimental specimens have been produced and tested to failure. A nonlinear finite element method is adopted throughout the T-joint, which is taking into account the possible high-stress concentration positions, the nonlinear properties of both the core and the glue materials and the nonlinear displacement deformation of the T-joint. In this way we succeeded in making a significant contribution to furthering the understanding of the response and failure of sandwich T-joints. The effect of some design parameters of such joints affecting joint strength and flexibility is also investigated.