Experimental investigations of bolted, adhesively bonded and hybrid bolted/bonded single-lap joints in composite laminates

The work presented in this paper covers an experimental study on the tensile property of the single-lap joints in carbon-fiber reinforced bismaleimide (BMI) resin composite laminates. This kind of composites are widely used in the aerospace industry for its high-temperature resistance. Three configurations of joints were involved in this paper, which were bolted, adhesively bonded and hybrid bolted/bonded single-lap joints. Effect of stacking sequence and width to diameter (W/D) ratio of the composite laminates were discussed on the tensile property of the single-lap joints. It was found that the stacking sequence and W/D ratio were important in the design of the joints. The hybrid joint had the highest tensile strength, but the secondary bending was serious. The test results indicated that the bolts in the hybrid joints could enhance the tensile property after the adhesive failure. The adhesively bonded joint achieved the lowest strength, and the failure mode was brittle failure.