DYNAMIC-MECHANICAL PROPERTIES OF AUTOMOTIVE THIN SHEET STEEL IN TENSION, COMPRESSION AND SHEAR

Thin sheet steel has been tested at different strain rates ranging (10 (-3) to 10(+3) s(-1)) under different deformation modes. The specimens were cut from thin sheet at 0 and 90 degrees with respect to the roll ing direction. It was found that pre-strained specimens in tension are characterised by higher initial yielding and a strong decrease of the strain hardening. Specimens at 90 degrees show at increasing strain r ate a higher yielding stress with respect to 0 degrees specimens empha sising the importance of anisotropy effects in sheet metals. Furthermo re, the equivalent flow curve at relatively large strain values do not coincide at different deformation modes (shear, compression and tensi on).