Weight reduction of automobile parts is the very important issue in the automotive industry. Thus, many interior automotive parts such as door trim, dash board, various operation buttons and pedals are made of various light weight engineering plastic materials.

On the design point of view, these plastic automotive components must satisfy the safety of passengers in the accident. However, the plastic components have disadvantage that some sharp edges can be generated during collision accidents. Since the sharp edge may cause critical secondary damage on the occupant, it must be predicted and prevented in the early design process by finite elements simulations.

In order to predict sharp edges in the plastic automotive components by finite element methods, dynamic material behavior of the plastic materials must accurately be identified. In particular, it is necessary to know the failure strain of the materials under various loading conditions.

In this thesis, we showed various experimental results on the dynamic behavior of automotive plastic materials, especially on the large deformed polymer materials. Since it is not possible to consider all of the loading conditions, in the present study, materials were tested under several typical loading paths and under various strain rates.

Since the polymer material behaves as a rubber material, it generally undergoes a very large failure strain. In order to measure the large strain of the material used in the experiment, a digital image correlation(DIC) technique was used.

Additionally the digital image in order to confirm the reliability of the measurement results using the correlation technique, and compared the results of the measurement in several ways. The reliability of the digital image correlation method was verified by comparing the strains measured with strain gages and an extensometer.

In this study, high strain rate behaviors of automotive polymer materials were verified and the failure strains under tensile, shear, plane strain and notched condition were measured. Since the behavior of the polymer material is different with the elasto-plastic behavior of metals, true stresses were calculated with the continuously varying real cross sectional areas of the specimens. Results also showed large difference between real true stress and the one calculated from volume constancy condition generally used in metals.