Fracture toughness of particle filled fiber reinforced polyester composites

Abstract

Abstract Fracture behavior of polyester composite systems, polyester mortar and glass fiber reinforced polyester mortar, was investigated in mode I fracture using single edge notched beams with varying notch depth. The beams were loaded in four‐point bending. Influence of polymer content on the flexural and fracture behavior of polyester composites at room temperature was studied using a uniform Ottawa 20–30 sand. The polymer content was varied between 10 and 18% of the total weight of the composite. The flexural strength of the polyester mortar systems increase with increase in polymer content while the flexural modulus goes through a maximum. The critical stress intensity factor ( K IC ) for the optimum polyester mortar (14%) was determined by two methods including a method based on crack mouth opening displacement. The K IC for polyester mortar is linearly related to the flexural strength. Polyester mortar (18%) reinforced with 4% glass fibers was also investigated, and crack growth resistance curve ( K R ) was developed with crack extension (Δ a ). A model has been proposed to represent the fracture toughness with change in crack length, K R ‐ Δ a relationship, of fiber reinforced polyester composite.