Abstract The use of z-pins to controllably increase the electrical conductivity and to detect damage in sandwich composites is investigated. Sandwich materials with polymer foam core or balsa wood core were reinforced in the through-thickness direction with z-pins made of metal (copper, titanium) or carbon fibre composite. The through-thickness electrical conductivity of the sandwich composites was increased by up to nearly seven orders of magnitude by z-pins, although the in-plane conductivity was not affected significantly. The increase to the through-thickness conductivity was controlled by the electrical properties, volume content and/or insertion angle of the z-pins. Due to the increased conductivity, z-pins were used for in-situ and real-time electrical-based monitoring of damage caused by crushing or skin-core interfacial debonding of sandwich composites. In addition, the z-pins increased the flatwise compressive strength and in-plane fracture resistance of the sandwich composites. It is demonstrated that z-pins can increase multiple properties concurrently, including the electrical and mechanical properties, and also provide the functionality for in-situ real time damage detection.

中文翻译：

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多功能Z型销夹层复合材料的电学性能

摘要 研究了使用 z-pin 来可控地增加电导率并检测夹层复合材料中的损伤。带有聚合物泡沫芯或轻木芯的夹心材料在厚度方向上用金属（铜、钛）或碳纤维复合材料制成的 z 销进行了加固。尽管面内电导率没有受到显着影响，但夹心复合材料的全厚度电导率通过 z 引脚增加了近七个数量级。全厚度电导率的增加由 z 引脚的电性能、体积含量和/或插入角控制。由于电导率增加，z-pin 用于对夹心复合材料的压碎或皮芯界面脱粘造成的损坏进行原位和实时的基于电气的监测。此外，z-pins 增加了夹层复合材料的平面压缩强度和平面内断裂阻力。结果表明，z-pins 可以同时增加多种性能，包括电气和机械性能，并提供原位实时损伤检测的功能。