부산대학교 도서관

The purpose of the present paper is to investigate the mechanical behavior of mild steel at quasi-static () and different rates of dynamic tensile () and compressive () strain rates. Quasi-static experiments are conducted on a universal testing machine to study the stress-strain behavior of mild steel. A hydropneumatic machine and a modified Hopkinson bar are used to investigate the dynamic tensile behavior of mild steel specimens at medium and high strain rates, respectively, whereas the specimens are tested on a split Hopkinson pressure bar to acquire understanding of the strain rate sensitivity of mild steel under dynamic compression. The effects of a pulse shaper and gauge length of the specimen in the dynamic compression tests are investigated. High-speed photography has been used to monitor the deformation of the specimen at high strain rate experiments. The applicability of the existing Cowper-Symonds and Johnson-Cook material models to represent the mechanical behavior of mild steel in a plastic zone is examined. Finally, the fractographs of the tested tensile specimens are studied using a scanning electron microscope. [ABSTRACT FROM AUTHOR]