45钢冷滚打成形Johnson-Cook本构模型参数标定及修正方法

Parameter calibration and correction of Johnson-Cook constitutive model for 45 steel cold roll-beating

冷滚打成形技术是在金属材料冷态下,使用具有一定形状的滚打轮不断击打工件表面,迫使金属局部产生塑性变形并逐渐累积的一种增量冷塑性成形方法。为了建立更为精准可靠的冷滚打成形的有限元模型,本文分析了冷滚打成形原理及其成形特点,采用下山单纯形法建立了以材料J-C本构模型参数为对象的多元函数修正方法,并以45钢为例,结合冷滚打实验和有限元仿真,修正了通过分离式Hopkinson压杆实验测定的J-C本构模型中的4个参数。结果表明相比于修正前,采用修正后的J-C本构模型参数得到的仿真结果能够准确描述不同加工参数下的冷滚打成形力,与实验结果的最大误差为9.8%。

Cold roll-beating technology is the use of metal materials in the cold at a certain degree of elastic-plastic deformation capacity,and the use of a certain shape of the roller and high-speed rotation constantly hits the surface of the workpiece,forcing the surface of the local flow of plastic deformation by a plastic near net forming method.In order to establish a finite element model for more accurate and reliable cold roll-beating,this paper analyzes the principle of cold roll-beating and proposes the correction of J-C constitutive model parameters by using the downhill simplex method of multivariate function.45 parameters of J-C constitutive model are calibrated by separating the Hopkinson pressure bar experiment.The cold roll-beating experiment is carried out under the condition of different processing parameters,with the simulation model established by the finite element software ABAQUS.The J-C constitutive model parameters are modified by the simplex method and the finite element method.The results show that the simulation results obtained by using the modified J-C constitutive model parameters can accurately reflect the cold roll-beating force under the condition of different processing parameters,with the maximum error of the experimental results 9.8%.