Low-velocity impact performances of CFRP laminates containing 3D microvascular channels

Microvascular self-healing composites are suitable for repairing low-velocity impact (LVI) damage in the structures, and their original mechanical performances need in-depth study. In this paper, the LVI and compression after impact (CAI) performances of composite laminates containing 3D microvascular channels were investigated experimentally. Then the microvascular laminates models were established by equating the channels as regions with discounted material properties, which were calculated by representative volume element (RVE) models of the channels. The validated models were used to analyze the damage mechanism of the microvascular laminates and parameter influence of the channels. The results indicate that the microvascular channels had small influence on the impact performances of the laminates, only slightly changing the damage configuration. The microvascular channels would not rupture before the impact damage extends to their regions when the impactor did not impact the channels directly. The effects of the impact energy, channel distribution and spacing on the impact performance of the microvascular laminates were obtained. And the design criteria based on damage tolerance design specification for channel spacing were proposed. This study offers a reference and basis for the design of microvascular self-healing composite structures.