Research On M-Paul Dynamic Constitutive Relation Of Q235B Steel

With the development of computer technology and numerical methods,numerical simulation becomes an important method in the research of building structure under impact and blast.The stress-strain relationship of material becomes more complex under dynamic loading,so it is crucial for the accuracy of numerical simulation result to choose a reasonable and effective material constitutive relation.At present,the foreign studies on the dynamic constitutive relation of metal materials have become more and more mature,Johnson-Cook,Zerilli-Armstrong,Khan-Liang and other constitutive relations have been widely used in engineering field.However,there was few dynamic constitutive relations adopted in the domestic metal materials studies,and most of them followed the above material model or modified on the basis of Johnson-Cook model.This paper studied the dynamic mechanical behavior of Q235 B steel on the basis of Paul constitutive model.After that,the Modified Paul(M-Paul)constitutive relation was proposed,and the material parameters were calibrated.Then,the accuracy of material model was verified combining the ballistic test and numerical simulation.The main research work is as follows:1.Establishment of M-Paul dynamic constitutive relation for Q235 B steelThe expression and parameter measurement method of Paul constitutive model were studied,and the model was compared with Modified Johnson-Cook constitutive model.Then,the material parameters of Paul constitutive model were calibrated based on ABAQUS/Standard solver and Isight numerical optimization software.And it was found that the temperature softening behavior of Q235 B steel couldn't be described properly by temperature related item of Paul constitutive model,so the M-Paul constitutive model was proposed by modifying the initial model.Finally,the accuracy of M-Paul constitutive model was verified by comparing the predicted flow curves of M-Paul and Modified Johnson-Cook constitutive model with test result.2.Research on ballistic test of Q235 B and Q460 D steelThe ballistic tests for blunt projectile penetrating Q235 B steel target plate and ogival projectile penetrating Q460 D steel target plate were conducted by one-stage light-gas gun,the initial and residual velocity of projectile impacting target plate were recorded by high-speed camera system.And the ballistic limit velocity of two groups of ballistic test was obtained by least square method.Then the test results were analyzed,and the failure modes of Q235 B and Q460 D steel target plate under projectile impact were obtained.3.Numerical simulation study on ballistic test for blunt projectile penetrating Q235 B steel target plateBased on ABAQUS/Explicit solver,the corresponding numerical model of ballistic test for Q235 B steel was established,the Modified Paul,Modified Johnson-Cook and Johnson-Cook constitutive model was chosen as the strength model respectively,and the Modified Johnson-Cook fracture criterion was chosen as the failure model.The corresponding numerical simulation was carried out,and the results were compared to verify the accuracy of M-Paul constitutive relation.