Ti-6Al-4V合金高速切削仿真Johnson-Cook本构参数优化

OPTIMIZATION OF JOHNSON-COOK PARAMETERS IN FINITE ELEMENT SIMULATION OF HIGH-SPEED CUTTING TI-6AL-4 V ALLOY

为了获得能准确描述工件材料在高速切削过程中高温、高应变率、大变形耦合作用下的塑性流动行为的Johnson-Cook(J-C)本构参数,使其适用于高速切削仿真。采用响应曲面近似法和多目标优化方法对Ti-6Al-4V合金的J-C本构参数进行优化,并将其应用于高速切削模拟仿真。结果表明,优化后的本构参数能够在很广的切削速度范围内准确地描述工件材料在切削过程中的塑性流动行为,由此模拟得到的切屑形貌与平均切削力可以和实验结果很好地吻合。

In order to obtain the Johnson-Cook(J-C) constitutive parameters that can exactly reflect the plastic flow behavior of the workpiece material under the coupling effect of high temperature, high strain rate and large deformation occurred in high-speed cutting, and make it to suitable for the high-speed cutting simulation. The J-C parameters of Ti-6 Al-4 V was optimized with using the response surface approximation and multi-objective optimization methods to apply it to high-speed cutting simulation. Results show that the optimized constitutive parameters could describe the plastic flow behavior of the workpiece material accurately in a wide range of cutting speeds, and the simulated chip morphologies and the average cutting forces are in good agreement with the experimental results.