Material Modelling of Semi-Crystalline Unfilled Polymers

Abstract: With development of polymer science, demands of polymer based products are increasing in automotiveindustries. As a part of product development a significant amount of efforts have been devoted towardsmaterial modeling for polymers which represent the material behavior at different working conditionsusing finite element analysis. In this thesis, we consider polymers with isotropic behaviour. Themethod involves, raw material data from experimental tests, tensile tests and three-point bendingtests with the video extensometer at different strain rates and ambient environmental conditions. Thementioned tests along with the data from the tests were established in a simulation model whichtakes into account the theory of viscoelastic and viscoplastic behaviour of polymers in a finite elementsoftware. For each simulation suitable material models were compared. The performance of materialmodel is evaluated with previously performed tests, considering variation of mesh size and elementformulations. The video obtained from the video extensometer during the tests were used to performDigital Image Correlation and was investigated for the potential prediction of the material failurebefore it occurs. It was found that the currently used material model is not suitable after elastic limitfor polymers.i