Study On The Constitutive Model Of Q355B Steel And The Lode-related ASCE Fracture Criterion

Under the action of impact and explosion of building structure,the material will produce large plastic deformation and complex stress flow behavior.With the aid of the finite element numerical analysis method,the dynamic response of the building structure can be studied at a small cost.However,the material performance characterization greatly affects the accuracy of numerical simulation prediction.Therefore,the validity of the constitutive model and the fracture criterion play a vital role in the numerical simulation of the impact and explosion of the building structure.This paper studied the dynamic constitutive relationship of Q355 B steel,the main work has been done as follows:1.Calibration of Q355 B steel mechanical properties,constitutive model and fracture criterion parametersBased on the series of material tests,the parameter calibration of Mx J-C constitutive model and Mx J-C-Q constitutive model considering the yield stage was completed.It was found that Mx J-C-Q could more reasonably characterize the mechanical properties of the yield stage.In order to further explore the fracture characteristics under different stress states,a plane strain test was carried out,the calibration of the Lode-independent MJC fracture criteria and the Lode-related ASCE fracture criteria was completed,and the correlation between the fracture strain of Q355 B steel and the Lode parameter was analyzed.2.Test research on blunt projectile penetrating Q355 B steel targetThe blunt projectile penetration test of the 4mm thick Q355 B steel target was completed on the first-class light gas gun.The fracture mode and residual velocity of the target were obtained,and the ballistic limit was obtained by fitting the initial-remaining velocity of the projectile.3.Numerical simulation research on the penetration test of Q355 B steel targetA numerical model of target penetration was established using ABAQUS software,and three sets of parallel numerical calculations were carried out,the deformation and fracture behavior of the target were studied.The Mx J-C-Q constitutive model considering the yield stage and Lode-related fracture criteria were verified,the effect of Lode parameter on the deformation and fracture of Q355 B steel was discussed.The results indicated that the fracture strain and ballistic limit were overestimated by using MJC fracture criterion,especially the ballistic limit,which was about 38.36% higher than the test value;While the ballistic limit,residual velocity and fracture behavior simulated by the Lode-related ASCE fracture criterion were basically consistent with the test results.