The performance transition of C/SiC composites induced by redistribution of residual stress

The residual stress generated from temperature changes and interference fit of rivet plays a significant role in the performance of C/SiC composites. To gain a thorough understanding of the residual stress evolution mechanisms and their influences on C/SiC composites, this work carries out comprehensive experimental research combined with simulation analyzes. The results of quasi-static tension tests present that as the environmental temperature rises from room temperature to 800 °C, the stiffness of structure increases a lot, while the strength of riveted joints significantly decreases. Furthermore, it is found that the microscopic failure modes are also changed. The cyclic unloading-reloading tests for calculating the residual stress quantitatively are conducted to explain the failure evolutions of structures. The obtained results reveal an important connection between the residual stress states and the microscopic failure modes of C/SiC composites. The environmental temperature and interference riveted joint both can affect stress state around the open hole, which are significant factors determining the damage modes and structural performance. In the process of C/SiC composites design, it is necessary to pay attention to the processing parameters of rivet interference fit to meet the performance optimization under service conditions.