考虑固化残余应力影响的 Z-pin 增韧复材压缩性能预测方法

The Z-pinning technology can effectively improve the interlaminar properties of composite materials，yet the implantation of Z-pins causes fiber distortion，resin-rich zones，and reduced in-plane properties. This paper proposes a numerical method to predict the in-plane compressive properties of Z-pinned composites，with curing effects into consideration. A representative unit cell model is established by analyzing the fine morphology of the Z-pinned structure. Considering the time-dependent properties of the cure process，we develop a coupled thermo-chemo-mechanical multi-field model for Z-pinned structures. The residual stress field obtained from the previous calculation is introduced as a predefined field in the calculation of in-plane compressive performance，and the simulated results are in good agree⁃ ment with the experimental results. It is found that a large amount of residual stress accumulates around the Z-pin during the cure. Therefore，under compressive loads，weaker material properties around the Z-pin will first develop crack defects，gradually extending to the resin-rich regions. The presence of fiber orientation，resin-rich regions，and cure-induced residual stresses significantly reduce the in-plane compressive performance of Z-pinned composites.