Bearing strength of carbon fibre/epoxy laminate with direct measurement of hole deformation

The bearing strength of carbon fibre/epoxy laminates composite has been investigated with a new failure criteria instead of conventional load. A precise measurement of hole deformation allows to determine the failure load as a clear kink point on the load-displacement curve. The validity of the new failure criteria was evaluated by cyclic load tests. With the new failure criteria, the effect of bolt-hole clearance and the clamping force were re-evaluated. Effect of the gap between the specimen and bush was also investigated. The experiments show more than 0.1 mm clearance for 6.35-mm hole affect for the failure load but not maximum load. The tightening up torque affects both the failure and maximum load up to . The gap between specimen and bush strongly affect the maximum load but not failure load. These results give a design criteria for thickness tolerance for the cases of using collar on the hole. Significant deviation between conventional load and new failure load were found in several conditions.