Fracture Mechanical Trouser Taer Testing of thin polymer films

Abstract: Tensile and Trouser tear tests of thin packaging polymer films have been done successfully in this research thesis. Two different polymers (PP and LDPE) are used. Mode I and Mode III fracture tests have been used for crack propagation analysis. Several experiments are performed to calculate the material parameters. The research study includes the experimental test along with virtual tests using the FEM software Abaqus 6.12-1. ASTM standard 1938-08 is followed for specimen size and experiments are performed on Instron 5655 with 100 N load cell, Tetra Pak Package Lab at Lund. Repeatable and reproducible results are obtained for the principle directions (MD, CD and 45) for Tensile and Trouser Test for brittle and ductile film. Experimental and Numerical Tensile tests have been performed and validated on different crack shapes using MTS machine, BTH Material lab. Visual analysis is made using the Scanning Electron Microscope and polarized light microscope to analyze material and crack propagation behavior. Tearing force for crack propagation is extremely small compared to the Tensile tests. A detailed Essential Work of Fracture (EWF) study has also been made to further understand the behavior. The work will provide an aid to simulate the working conditions better to have a detailed understanding of the polymer behavior. Key Words: PP, Mode I , Mode III, Tensile test, ABAQUS simulation, Crack shapes, Tearing behavior, EWF, Polarized light, SEM microscope.