Theses and Dissertations

Issuing Body

Mississippi State University


Bouvard, Jean-Luc

Committee Member

Horstemeyer, Mark F.

Committee Member

Rhee, Hongjoo

Date of Degree


Document Type

Graduate Thesis - Open Access


Mechanical Engineering

Degree Name

Master of Science (M.S.)


James Worth Bagley College of Engineering


Department of Mechanical Engineering


Research areas within the automotive industry are dedicated to reducing the weight and emissions of vehicles. Through the application of lightweight materials, such as polymers, fuel consumption and production costs can be decreased. Therefore, understanding the mechanical responses and failure mechanisms of these materials is significant to the development and design of vehicular structural components. Experimental tests were performed to capture the time, temperature, and stress state dependence, as well as failure mechanisms and large-strain mechanical responses of polypropylene (PP) and copolymer polypropylene (co-PP). Alongside studying the mechanical responses of PP and co-PP, the deformation mechanisms associated with the ductile and brittle failures were also examined. By applying an Internal State Variable (ISV) model, the mechanical behavior of PP and co-PP under various strain rates and temperatures was predicted. Phenomenological, mechanics based failure criteria were also applied to the model to predict the ductile or brittle failure of the materials.