Experimental and numerical analysis of repaired stiffened carbon fiber-reinforced plastics panels under compression

Stiffened carbon fiber reinforced plastics (CFRP) panels have been widely used in the aerospace industry due to their high weight-specific mechanical properties but they are also susceptible to impact damage. Therefore, the research on the effects of various defects and repair methods on the damaged stiffened CFRP panels is of paramount importance. This paper presents an experimental and numerical study on the compression behavior of stiffened CFRP panels containing two types of initial defects with three repair methods i.e. mechanical repair, adhesively bonded repair, and scarf patch repair. Quasi-static compression mechanical tests were first performed on physical specimens. The buckling and post-buckling behaviors of the specimens were analyzed through experimental results. The finite element models were developed and validated through experimental results, based on which parametric studies on the influences of various delamination and repairing parameters to the load-carrying capacity of the stiffened CFRP panel were performed. The experimental and numerical results reported in this paper can serve as a general guideline for the selection of the most suitable repair method for various defected stiffened CFRP panels.