In this paper, a modified acoustic-plastic Johnson–Cook model for Ti–45Nb alloy was established, which can be used to reveal the metallic deformation behavior under ultrasonic vibration-assisted (TUV) forming. First, the experiments of traditional compression and TUV compression were carried out, the influence of vibration amplitude on yield strength, strain hardening coefficient and index, and strain rate hardening coefficient. The yield strength reduction is caused by the acoustic softening effect. The yield strength and strain hardening coefficient present a negative correlation with amplitude increase, the strain hardening index and strain rate hardening coefficient present a positive correlation with amplitude increase. Further, the accuracy of the developed constitutive model was quantitatively identified, the relative coefficient is as high as 0.954, the mean absolute percentage error less than 5.42%. On this basis, a user-defined subroutine was developed to implement the numerical simulation of the TUV forming processes using the finite element method, the results of numerical simulation and experiment are in good agreement, and prediction accuracy is as high as 95.25%. Therefore, the developed constitutive model can be well revealed the material deformation behavior and provides an application guide.

在本文中，建立了一种改良的Ti-45Nb合金声-塑性Johnson-Cook模型，该模型可用于揭示超声振动辅助（TUV）成形下的金属变形行为。首先，进行了传统压缩和TUV压缩的实验，振动幅度对屈服强度，应变硬化系数和指标以及应变速率硬化系数的影响。屈服强度的降低是由声软化效应引起的。屈服强度和应变硬化系数与振幅增加呈负相关，应变硬化指数和应变速率硬化系数与振幅增加成正相关。此外，定量确定了开发的本构模型的准确性，相对系数高达0.954，平均绝对百分比误差小于5.42％。在此基础上，开发了用户自定义子程序，通过有限元方法对TUV成形过程进行了数值模拟，数值结果与实验结果吻合良好，预测精度高达95.25％。因此，所建立的本构模型可以很好地揭示材料的变形行为，并提供应用指导。