The dynamic mechanical constitutive equation of concrete under high temperature

摘要

Based on the test by the split Hopkinson Pressure Bar (SHPB), in this paper the research on the dynamic mechanical properties of concrete under high temperature has been conducted, the influence law of temperature and strain rate on the mechanical properties has been analyzed, and the dynamic stress-strain curves of concrete under high temperature have been obtained. Analysis indicate that the concrete strain rate hardening effect is coupled with the high temperature weakening effect. Therefore, on the basis of classical damage theoretical model, in accordance with the concrete high-temperature dynamic mechanical characteristics, a unified equation is established to describe the whole process of concrete dynamic stress-strain relationship under high temperature, which is well coincided with the test results.