碳/碳编织复合材料连接结构的拉脱性能分析

Pull-through performance of the C/C composite joints are studied through experiments and numerical simulations. Failure process, mode, and pull-through strength are investigated experimentally for bolt forms and countersunk head angles. The results show that the bolt form has a significant effect on the pull-thought performance of the structure. The load-displacement curve of protruding head bolts has an obvious linear stage. The failure mode is close to brittle failure. The load-displacement curve of countersunk head bolts is nonlinear. A non-linear contact model, based on the Hashin failure criterion, is established using ABAQUS. The model is validated by comparing failure modes and load-displacement curve to experimental results. The progressive damage and failure mechanism of the joints are obtained, and the influence mechanism of parameters(bolt form, countersunk head angle and constraint area) on pull-thought failure is given. The results show that the pullout failure load of the structure increases first and then decreases as the increase of the countersunk angle, and the failure load reaches the peak near 110°. Failure mode changes from shear failure to bending failure due to increase of constraint area.