Failure Analysis of CFRP Multidirectional Laminates Using the Probabilistic Weibull Distribution Model under Static Loading

Abstract

The application of carbon fiber reinforced polymer (CFRP) Multidirectional (MD) laminates in aircraft structure have motivated the manufacturers to tailor the mechanical strength in desired directions. The complex stress field owing to multiple orientations with the loading direction increases the intricacy of failure analysis. Hence, the macroscopic and microscopic fracture behaviour of MD CFRP laminates under static loading needs to be explored further. In this study, four different MD CFRP laminates were fabricated using IMA/M21 prepregs by the autoclaving technique. Effect of fiber orientation on static strength i.e. tensile and compressive strength was studied. The strength decreased with the increase in orientation angle. Scanning electron micrographs revealed that irrespective of the lay-up sequence individual layers failed parallel to the fiber direction. Fiber breakage and delamination were the major failure modes in tensile specimens while kinking, matrix failure, in-plane shear, stepped fracture, and fiber-matrix debonding were dominated in compression specimens. The theoretical and experimental data was in good agreement with the Weibull distribution model.