The Effect of Micro Damages to Mechanical and Electrical Behaviors of Carbon Fiber Reinforced Polymer: a Review

This paper presents a brief review of the effect of micro damages in carbon fiber reinforced polymer (CFRP) on its mechanical and electrical behavior. CFRP composites offer strength and stiffness properties in the longitudinal direction, but they will quickly develop cracks along the fibers. There are three types of micro damages in the composite: fiber breakage, matrix cracking, and interfacial debonding. The role of these damages can be investigated by conducting multiscale modeling. The representational volume element (RVE) and the repeating unit cell (RCU) approach will be applied at a specific location by multiscale elements and run parallel to global analysis. The idea is to create a model in each scale (macro, meso, and micro scales) so that the model can be connected. For mechanical behavior, the damage appearance directly correlates with mechanical properties drop, which may be dangerous when the composite is applied as load-bearing structures. Considering the carbon fiber has high conductivity, the composite can also be used as a sensor for detecting crack appearance, applicable for structural health monitoring. In this case, the electrical behavior must be evaluated carefully before the implementation. One of the remaining issues for the application is understanding the effects of micro damages on electrical behavior. Several efforts to solve this issue are explained in this paper. Understanding the relationship between these damages to the behaviors can be useful to develop technology that improves the crack resistance of CFRP composites, preventing or delaying matrix cracking and delamination.