镍铝青铜切削加工本构模型参数辨识

摘要

镍铝青铜材料因具有较高的强度、耐磨损及优异的抗应力腐蚀特性而广泛用于螺旋桨的制造中。为了建立其在高应变率条件下的本构关系，提出一种切削加工过程中 Johnson−Cook 模型参数辨识的新方法。该方法综合了 SHPB 动态压缩实验、可预测切削力模型及直角切削实验。首先，根据 SHPB 实验得到镍铝青铜在不同应变率和温度下的真实流变应力−应变曲线；然后，建立关于预测流变应力和实验流变应力的目标函数，将 SHPB 实验辨识的本构参数作为初值，采用 PSO 算法反演得到最终的本构参数；最后，对可预测切削力模型和有限元仿真获得的切削力进行对比，验证了所辨识参数的准确性。%The material of nickel aluminum bronze (NAB) presents superior properties such as high strength, excellent wear resistance and stress corrosion resistance and is extensively used for marine propellers. In order to establish the constitutive relation of NAB under high strain rate condition, a new methodology was proposed to accurately identify the constitutive parameters of Johnson−Cook model in machining, combining SHPB tests, predictive cutting force model and orthogonal cutting experiment. Firstly, SHPB tests were carried out to obtain the true stress−strain curves at various temperatures and strain rates. Then, an objective function of the predictive and experimental flow stresses was set up, which put the identified parameters of SHPB tests as the initial value, and utilized the PSO algorithm to identify the constitutive parameters of NAB in machining. Finally, the identified parameters were verified to be sufficiently accurate by comparing the values of cutting forces calculated from the predictive model and FEM simulation.