Investigation of the Low-Velocity Impact and Compression after Impact Performance of CFRPs

Abstract

Low-velocity impacts (LVI) during a structure’s service life may affect the mechanical properties of carbon-fiber–reinforced composites (CFRP) and, consequently, their structural performance. Accordingly, it is crucial to consider this issue in the design steps of composite structures. In the present study, experimental procedures and numerical modeling have been implemented to predict the damage induced by LVI and its influence on the residual compressive strength of carbon/epoxy laminates. For numerical simulation, a user-defined subroutine (VUMAT) is utilized in commercial finite element software ABAQUS/Explicit. The first step of numerical simulations corresponds to the collision of the impactor with the composite plate. Then, the impacted composite plate is subjected to a compression test to estimate the residual compressive strength. Experimental tests are completed by performing LVI tests to validate the numerical simulation results in three impact energy levels of 10, 15, and 20 J. The results reveal good agreement between experimental and numerical methods. According to the results, 18.1%, 28.7%, and 33.0% reductions in compressive strength of the carbon/epoxy composites were observed due to LVI with energy levels of 10, 15, and 20 J, respectively.