Determination of Holmquist-Johnson-Cook model parameters for sandstone

HJC model has been widely used to describe the dynamic failure process of concrete. However,due to the reason that HJC model contains many parameters,the accurate determination on the parameters of HJC model for rock materials is a challenge. In this paper,the authors performed some laboratory experiments to determine the HJC param- eters of sandstone samples that were collected from Weiyuan City,Sichuan,China. Specifically,the authors determined the elasticity modulus,Poisson’s ratio,and uniaxial compressive strength of sandstone by uniaxial compression experi- ments,and the tensile strength by Brazilian disk splitting tests. The strength,strain rate,pressure and damage model constants were determined by fitting the HJC model to the experimental data obtained from the triaxial compression tests and uniaxial SHPB tests. The obtained HJC parameters were used to numerically simulate the SHPB tests of the sandstone samples using finite element program LS-DYNA. The results show that the stress-strain curve predicted by the HJC model is in good agreement with the experimental data. The mean error of dynamic peak stress and corre- sponding stain obtained by numerical simulation does not exceed 10% . This demonstrates the rationality and validity of the experimental method for determining the HJC parameters.