剪切增强和应变率效应对混凝土类材料状态方程的影响OA

To investigate the shear-enhanced compaction effect and strain-rate effect on the equation of state(EoS)of concrete-like materials subjected to blast and impact loadings,high-fidelity numerical simulations were performed based on two types of EoS behavior tests for cement mortar,including hydrostatic compression tests and flyer-plate impact tests.These simulations employed the Kong-Fang hydro-elasto-plastic model for concrete-like materials and were implemented using the smoothed particle Galerkin(SPG)algorithm in LS-DYNA,enabling accurate reproduction of complex dynamic mechanical behaviors,including the shear-enhanced compaction effect and strain-rate effect.Based on the high-fidelity numerical simulations described above,a quantitative analysis was conducted to investigate the influence of the shear-enhanced compaction effect and strain-rate effect on EoS behavior of concrete-like materials,and the challenges associated with eliminating the shear-enhanced compaction and strain-rate coupling effects in flyer-plate impact tests were systematically identified.The results demonstrate that the Kong-Fang model,when combined with the SPG algorithm,can accurately simulate the complex dynamic mechanical behaviors of concrete-like materials,including shear-enhanced compaction effect and strain-rate effect.To achieve high-precision simulation of dynamic mechanical behaviors of concrete-like materials subjected to blast and impact loadings across high-medium-low pressure ranges,it is essential to establish an EoS with a wide-range pressure based on experimental data from EoS behavior tests.However,shear-enhanced compaction and strain-rate coupling effects should be eliminated when using flyer-plate impact test data to calibrate the EoS parameters.A paradox arises in the establishment of EoS with wide-range pressure for concrete-like materials,and the application of numerical iteration correction methodology may represent an effective approach to resolving this challenge.These findings provide a theoretical foundation for the future development of a numerical iteration correction methodology to eliminate the shear-enhanced compaction effect and strain-rate effect on the EoS of concrete-like materials,thereby facilitating the establishment of a high-precision EoS with a wide range of pressure for concrete-like materials subjected to impact and blast loadings.