Compressive fatigue behavior of low-velocity impacted thermoplastic composite laminate

In this paper, residual compressive strength and compression-compression fatigue tests of two kinds of AS4/PEEK laminates with low-velocity impact damage were carried out to study the damage propagation characteristics. It was found that local buckling occurred around the impact dent and extended perpendicularly to the loading direction under fatigue compression loading. The expansion process of local buckling could be divided into three stages, and the damage mechanism of each stage was discussed. The experimental results showed that the impact damage and residual fatigue life both were quite dispersed under the same impact energy. A laminate with more severe impact damage had shorter residual compressive fatigue life, and the depth of impact dent could be used as an effective index to characterize the severity of impact damage and the residual fatigue life.

Automated summary

This study conducted residual compressive strength and compression-compression fatigue tests on two types of AS4/PEEK laminates with low-velocity impact damage to investigate damage propagation characteristics. It was found that the depth of impact dent is a key indicator of the severity of impact damage and residual fatigue life. Results showed that a laminate with more severe impact damage had shorter residual compressive fatigue life.