Constitutive modeling for large deformation behavior of thermoplastic olefin

A constitutive model has been developed to capture the rate-dependent large deformation behavior of the polypropylene (PP)/elastomer/inorganic filler ternary phase thermoplastic olefin (TPO). As the TPO exhibits elastic behavior of each constituent phase during elastic deformation and shear yielding of PP matrix after linear elastic loading. The elastic modulus of the composite is predicted using micromechanics theory. The viscoplastic behavior of TPO is described by a model which includes rate and temperature dependent yield, strain softening, and strain hardening. The material properties of the model are obtained from the uniaxial tensile test and then the model is examined for its ability to predict the response in deformation. It is proved that the large deformation features of the TPO composites are well described by the constitutive model.