STUDY ON THE EFFECT OF STRAIN RATE AND TEMPERATURE ON THE MECHANICAL BEHAVIOR OF POLYPROPYLENE AND THERMOPLASTIC OLEFIN

Abstract

In this study, the strain rate dependent tensile properties of Polypropylene (PP) and Thermoplastic olefin (TPO) were investigated under the high strain rate by using the Split Hopkinson Pressure Bar (SHPB). The SHPB is the most widely used apparatus to characterize dynamic mechanical behavior of materials at high strain rates between 100/s and 10, 000/s. Also, the dynamic properties of TPO and PP were measured under temperature from -35 ℃ to 85 ℃. The SHPB test is based on the wave propagation theory which was developed to give the stress, strain and strain rate in the specimen using the strains measured in the incident and transmission bars. In addition, to verify the strain data obtained from SHPB, the strain distribution of the specimen was photographed with a high-speed camera and the strain data obtained through the Digital Image Correlation (DIC) and compared with the strain value from the SHPB test.