Experimental determination of design allowable for composite sandwich joints

Abstract

Various joint types are used in composite sandwich structures to transmit different types of load. Different loads also create different states of stress in the constituents both in direction and magnitude and cause various failure modes. In regulations for commercial aircrafts, it is required to formulate the design allowable for sandwich joints. However, it is not easy to determine the design allowable because the failure behavior of sandwich joints is so complicated. This paper deals with the investigation of the failure behavior of six different types of sandwich joint to determine the design allowable. Test includes the shear and pull-out loadings separately. The progress of failure in the joints with various configurations and material systems has been discussed in detail and then an idea to determine the design allowable in the joints was proposed.