Polymer matrix composites that also contain carbon fiber reinforcement can be given a secondary function in addition to load bearing due to the electrical conductivity of the reinforcing fiber. We investigated how to measure the deformation of a composite by measuring the resistance of the carbon fiber and indicate its current or previous overload. We found that the resistance of the carbon fiber bundle initially increases linearly and then progressively during the testing of the specimens, and finally, when the fiber bundle snaps, the circuit breaks. We have shown by cyclic testing that overload exceeding reversible deformation can be detected and measured by examining the first derivative of the resistance change with respect to deformation. Based on our results, electric measurements of either an only carbon fiber-reinforced composite or a hybrid composite can be used to detect a possible previous overload of a component with an unknown load history.

由于增强纤维的导电性，还含有碳纤维增强材料的聚合物基复合材料除了承载能力外，还可以提供辅助功能。我们研究了如何通过测量碳纤维的电阻来测量复合材料的变形并指示其当前或之前的过载。我们发现碳纤维束的电阻在试样的测试过程中最初呈线性增加，然后逐渐增加，最后，当纤维束断裂时，电路断开。我们已经通过循环测试表明，通过检查电阻变化相对于变形的一阶导数，可以检测和测量超过可逆变形的过载。根据我们的结果，