Process-induced failure mode transition of compression molded discontinuous carbon fiber composites: From coupon to component level

Discontinuous carbon fiber composites have been reported to be damage tolerant materials with insensitivity notches and defects. Meso-scale mechanisms crack arresting are responsible for high apparent fracture toughness pseudo-ductility. This work studies the effect of manufacturing structure formation on mechanical behavior stochastic sheet molding compounds based thermosetting prepreg platelets a length 50 mm. The process–structure–property–performance relationship is analyzed by non-destructive characterization bending tests component level. Model components various preform stack placement scenarios were compression molded investigate different flow conditions, weld lines artificially introduced experimental findings revealed process-induced failure mode transition from pseudo-ductile brittle behavior. Low-flow showed highly non-linear response large deflection values energy absorption. Higher in-mold material caused at significantly lower deflections considerable reduction absorbing capacity. Increased also reduced stiffness maximum load values. Weld exhibited major strength compared pristine configuration. Full-scale high-resolution X-ray computed tomography scans differences in local orientation state, increased levels waviness porosity, as well asymmetric distribution