An Improved JH2 Model for Modelling Rock Fracture under Blasting and Impact Loads
The JH2 model is widely used to simulate the dynamic behavior of brittle materials,but there are some issues in its strength criterion and damage definitions.Therefore,an improved JH2 model is proposed in this paper for modeling the rock material under the blasting impact loads.First,the initial yield surface and nonlinear damage scale factor are added to the strength model,the tensile and compressive damages are treated asymmetrically,and the volume plastic strain is introduced into the compression damage.After the implementation of the model into LS-DYNA material subroutine,a series of simulations are carried out for the element tests,split Hopkinson pressure bar(SHPB)dynamic splitting tests,and rock blasting tests.The results show that the improved JH2 model overcomes the limitations of the original JH2 model in damage evolution of tension-compression asymmetry,nonlinear strain hardening behavior,Lode angle effect and volume behavior,which verifies the accuracy and application potential of the improved JH2 model.
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