Multiscale performance analysis and optimization of a composite clamp plate for leaf spring assembly considering fiber orientation distribution

Abstract

Abstract The growing demand for lightweight solutions in automotive engineering has propelled the adoption of fiber-reinforced thermoplastic composites, necessitating precise characterization of their process-induced mechanical properties. This study develops an integrated multiscale methodology addressing injection-molding-induced fiber orientation heterogeneity in structural components. Through synergistic integration of injection molding simulation, mesoscopic constitutive modeling, and macroscopic structural analysis, we systematically investigated failure mechanisms in automotive leaf spring clamp plates. The proposed framework successfully identifies gravitational segregation during vertical molding as the root cause of terminal fracture under operational loads. Subsequent design optimization implements (1) reorientation of the injection direction to horizontal and (2) localized wall thickness reduction from 37 mm to 19.86 mm. These interventions collectively reduce the maximum principal stress by 19% (from 231 MPa to 187 MPa) while achieving a 12.8% mass reduction (from 780 g to 680 g), demonstrating the concurrent enhancement of structural reliability and lightweighting efficacy.