Composite material properties evaluation based on the Rational Experimental-Computational Correlation (RECC)

Fiber reinforced polymer (FRP) composites are multi-scale and heterogeneous, therefore, the reliable prediction of their failure modes and strength is not a simple task. This review hinges on answering the need for improved methods of strength evaluation via judicious combination of experimental testing and computational modeling. The present report focuses on how experimental approaches and advanced multiscale simulations should range simultaneously from micro-scale elementary specimen testing through coupon and component scale tests until the full assembly level based on the modified Carbon Fiber Reinforced Polymer (CFRP) pyramid of testing and design for more reliable aircraft structures. This illustrates the progressive refinement of the approach known as the Rational Experimental-Computational Correlation (RECC). RECC is used to correlate finite element (FE) modeling of the failure mechanisms including matrix cracking, fiber pull-out, delamination, and interface debonding, on the one hand, with the experimental results obtained from quasi-static mechanical testing equipped with Digital Image Correlation (DIC) for displacement mapping and strain visualization. The current review also highlights the importance of multi-scale characterization and modeling of hierarchically structured materials where micro-macro interaction contributes strongly to the observed and predicted deformation response. The paper recommends a comprehensive approach consisting of full field mapping and maintaining systematic connection between coupon-level and structural scale consideration, with further upscaling to higher dimensional studies of ready articles such as key aircraft structures (stringers, ribs and complete wings). Being able to link micro-macro properties through multiscale simulations holds the key to improving the reliability of strength prediction in aerospace applications.