高温条件下基于虚场法的钛合金弹塑性参数识别与提取  

Identification and Extraction of Elastic-plastic Parameters of Titanium Alloy at High Temperature Based on Virtual Field Method

作　　者：李奇涵[1] 马翔飞 高嵩[1] 桑晔 王志远 孟尖尖 马祥 LI Qihan;MA Xiangfei;GAO Song;SANG Ye;WANG Zhiyuan;MENG Jianjian;MA Xiang(School of Mechatronic Engineering,Changchun University of Technology,Changchun 130012,China)

机构地区：[1]长春工业大学机电工程学院,长春130012

出　　处：《精密成形工程》2024年第2期55-61,共7页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金青年基金(51805045);吉林省科技厅重点攻关项目(20200401115GX);吉林省科技厅重点研发项目(20210201052GX)。

摘　　要：目的准确表述TC4钛合金的力学性能,对TC4钛合金进行了单轴热拉伸实验,使用虚场法识别和提取不同高温条件下TC4钛合金的弹塑性参数。方法在不同试验温度(650、700、750℃)下,选用TC4钛合金(Ti-6Al-4V合金),按轧制方向以应变速率为0.1 s^(-1)进行热拉伸试验。采用立体数字图像相关系统(DIC)测量试样的真实应变,得到真实应力-应变曲线,并捕捉热拉伸过程中的随机点,计算出试样的真实应变场。通过虚场法(VFM)在试件的弹性阶段设置不同虚拟位移场,建立虚场方程组以识别不同试验组中的弹性模量和泊松比,利用JC本构模型建立适合试件塑性变形阶段的虚场方程,使用K-Means聚类算法提取模型中的塑性参数。结果在考虑计算误差的情况下,使用VFM识别出的弹性模量、泊松比与参考数值的加权相对误差分别在4.8%、6.4%以下;提取出的塑性参数可以用于建立JC本构模型,弹塑性参数的识别和提取均符合预期。结论使用VFM可以有效识别出TC4在不同高温条件下的弹性参数,K-Means聚类算法在提取塑性参数方面的效果较为显著。In order to accurately represent the mechanical properties of TC4 titanium alloy,the work aims to carry out uniaxial hot tensile experiment to identify and extract the elastic-plastic parameters of TC4 titanium alloy by the virtual field method under different high temperature conditions.The TC4 titanium alloy(Ti-6Al-4V alloy)was selected for the hot tensile test at different test temperature conditions(650,700 and 750℃)with a strain rate of 0.1 s^(-1) according to the rolling direction.The true strain of the specimen was measured by a stereoscopic digital image correlation(DIC)system to obtain the true stress-strain curve,and the random points in the hot tensile process were captured to calculate the true strain field of the specimen.Different virtual displacement fields were set up in the elastic stage of the specimen by the virtual field method(VFM),a set of virtual field equations was established to identify the Young's modulus and Poisson's ratio in different test sets,and the JC intrinsic model was used to establish the virtual field equations suitable for the plastic deformation stage of the specimen,and the plastic parameters in the model were extracted by the K-Means clustering algorithm.Considering the computational errors,the weighted relative errors of Young's modulus and Poisson's ratio identified by the VFM and the reference values were below 4.8% and 6.4%,respectively.The extracted plastic parameters could be used to establish the JC intrinsic model,and the elastic-plastic parameters were identified and extracted in accordance with expectations.The elastic parameters of TC4 at different high temperature can be effectively identified by VFM,and the K-Means clustering algorithm has significant effect in extracting the plastic parameters.

关 键 词：TI-6AL-4V合金 VFM 参数识别 本构参数 热拉伸实验 

分 类 号：TG115.5[金属学及工艺—物理冶金]