冲击载荷下TC18钛合金力学性能模拟研究

Simulation Analysis of Mechanical Properties of TC18 Titanium Alloy under Impact Loads

摘要:

TC18钛合金在退火状态下的屈服强度非常高,进行动态力学性能测试存在一定困难,可优先考虑采用数值模拟方法对其动态力学性能进行研究,而数值模拟结果的精确性主要取决于合金本构方程的精确性。为了减少数值模拟与实验结果之间的差异,在Johnson-Cook模型的基础上做了调整,利用ABAQUS软件的子程序接口自定义了材料本构子程序UMAT,以代码的形式来扩展ABAQUS程序的功能。通过与ABAQUS/Standard软件分析结果以及实验结果的对比,验证了自定义材料本构子程序UMAT计算结果的精确性与可靠性。该研究可为TC18钛合金的结构设计提供参考。

Abstract:

TC18 titanium alloy displays very high yield strength in the annealed state, so it is difficult to test the dynamic mechanical properties.Constitutive models are enormously helpful numerical tools to predict its dynamic mechanical properties,tested difficultly by experiments. An exact constitute model plays an important role in developing a realistic finite element(FE) model of the dynamic mechanical properties. But, the correctness of FE is the main issue. The classic Johnson-Cook model leads to poor efficiency in predicting the dynamic mechanical properties. In order to reduce the difference between numerical simulation and experimental results, the modified classic Johnson-Cook model is established by the subroutine interface(UMAT) provided by ABAQUS. By comparing with ABAQUS/Standard analysis results and experimental results, the accuracy and reliability of the UMAT calculation results of the custom material constitutive subroutine are verified, which provides a reference for the structural design of TC18 titanium alloy.