Analysis of Failure Modes in Silicone Rubber Composites Reinforced with Short Glass Fibers

This study comprehensively examines the interplay between fiber reinforcement parameters and failure mechanisms in short glass fiber-reinforced silicone rubber (SGFSR) composites. Experimental evaluations conducted across varying fiber lengths (3, 5, 7, and 9 mm) and weight fractions (0.05 wt% to 50 wt%) reveal distinct correlations between structural properties and mechanical performance. Specimens reinforced with 7 mm fibers showed up to a 97% reduction in elongation at break, while those containing (40% wt% to 50 wt%) fiber content exhibited the lowest absolute elongation values, ranging from 5.8 mm to 10.3 mm. Fracture surface analysis revealed a transition in failure modes, fiber pull-out and matrix shear dominated at low fiber fractions (≤30 wt%). In comparison, higher concentrations (≥40 wt%) promoted brittle fracture via fiber breakage due to stress concentration and reduced interfacial adhesion. Additionally, fiber-matrix debonding and curing-induced void formation collectively compromise matrix integrity, further diminishing composite toughness. These findings provide valuable insights for refining fiber reinforcement strategies to improve mechanical resilience, durability, and practical applicability of elastomeric composites in load-bearing engineering applications.