Numerical modeling of fracture behavior of ductile polymeric films

Polymer films have been used in many applications such as coating, microfluidic, packaging etc. Various processing techniques have been used to manufacture polymer films with blown film extrusion and film casting being the prominent ones. Processing parameters such as blow-up ratio, drawing ratio, etc. have significant effect on the mechanical properties and fracture behavior of polymeric films. Essential work of fracture has been widely used to characterize the fracture behavior, and to measure the fracture toughness of ductile polymeric films using Essential Work of Fracture Method. Three-dimensional finite element method (FEM) modeling has been carried out to study the fracture mechanics of ductile polymer films. Experimental results from literature were used to validate the FEM model. The results show that increase in ligament length decreases plastic deformation along the fracture process zone. Furthermore, the numerical analysis explains the mechanics behind the reduction of out-of-plane buckling. According to the FEM findings, increase in yield stress and/or strain hardening slope reduces plastic strain along the fracture process zone. Also, thinner polymer films show higher essential work of fracture compared to thicker films