Dynamic Mechanical Behavior at Elevated Temperatures and High Strain Rates of Structural Stainless Steel Used in Civil Engineering

ASTM A240/A240M 304 structural stainless steel is a widely used structural material in civil engineering. In this study, by using the split Hopkinson pressure bar (SHPB) technique, the dynamic compressive mechanical behavior of this material was experimentally investigated at four different temperatures of 25 degrees C, 300 degrees C, 500 degrees C, and 700 degrees C and three strain rates of 1,000, 3,000, and 5,000 s-1. Quasi-static compressive test under the strain rate of 0.001 s-1 was also carried out in the material test system at temperatures of 25 degrees C, 300 degrees C, 500 degrees C, and 700 degrees C. Test results showed that flow stress of ASTM A240/A240M 304 stainless steel decreases with temperature increase but increases with increase of strain rate. Moreover, temperature becomes the main factor affecting material performance at 700 degrees C. Based on the measured stress-strain curves, the modified Johnson-Cook model was proposed as the constitutive stress-strain model for ASTM A240/A240M 304 stainless steel. It was shown that the proposed modified Johnson-Cook model is in good agreement with the experimental results. According to the proposed modified Johnson-Cook model, a user subroutine (VUMAT for Abaqus/Explicit) for ASTM A240/A240M 304 written in Fortran was developed and verified. The proposed constitutive model and user subroutine of ASTM A240/A240M 304 stainless steel can be used for structural analysis and finite-element analysis under high strain rates and elevated temperature. (c) 2020 American Society of Civil Engineers.