• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2021, Vol. 57 ›› Issue (2): 80-86.doi: 10.3901/JME.2021.02.080

• 材料科学与工程 • 上一篇    下一篇

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U型缺口试件微压剪试验及其有限元模拟

王堃1, 赵锡龙2, 郑韶先2, 李渊博2   

  1. 1. 兰州交通大学土木工程学院 兰州 730070;
    2. 兰州交通大学材料科学与工程学院 兰州 730070
  • 收稿日期:2020-03-20 修回日期:2020-09-20 出版日期:2021-01-20 发布日期:2021-03-15
  • 通讯作者: 赵锡龙(通信作者),男,1983年出生,博士,副教授,硕士研究生导师。主要研究方向为焊接接头微区力学性能测试及仿真。E-mail:zhaoxilong@mail.lzjtu.cn
  • 作者简介:王堃,女,1985年出生,讲师。主要研究方向为螺柱焊接装置设计。E-mail:wangkun@mail.lzjtu.cn
  • 基金资助:
    国家自然科学基金(51605384,51765030)和兰州交通大学校青年基金(2016011,2017049)资助项目。

Investigation on Small Punch Test with U-shaped Notch and Its Simulation

WANG Kun1, ZHAO Xilong2, ZHENG Shaoxian2, LI Yuanbo2   

  1. 1. School of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070;
    2. School of Materials Science and Engineering, Lanzhou Jiaotong University, Lanzhou 730070
  • Received:2020-03-20 Revised:2020-09-20 Online:2021-01-20 Published:2021-03-15

摘要: 在金属试件背部开U型缺口,利用微压剪试验装置对TC4钛合金薄板进行微区力学性能测试。采用ABAQUS软件建立背部开缺口微压剪试件有限元模型,结合有限元逆向反推技术获得TC4钛合金高三向应力状态下的局部力学性能参数,并分析等效应力和孔洞体积分数的变化规律。结果表明,随着压头的不断下压,试件缺口尖端等效应力不断增加,达到峰值应力1 150 MPa,缺口尖端孔洞体积分数逐渐增加到临界孔洞体积分数后迅速增大并导致试件失效破坏。试件上表面处,其孔洞体积分数较低;随着压头的进一步下压,缺口根部区域等效应力逐渐减小,而试件缺口根部区域和压头边缘区域都表现出较高的孔洞体积分数。当达到峰值载荷时,缺口根部区域路径方向上的应力三轴度从2.28降到-0.64,孔洞体积分数在缺口根部区域表现为最大值,而在路径末端相对较低,其分布趋势与应力三轴度相似。

关键词: TC4钛合金, 微压剪试验, 局部力学性能, U型缺口, 有限元模拟

Abstract: The local mechanical properties of TC4 titanium alloy sheet are tested for the specimens with a U-shaped notch on the back of the metallic material by a small punch test device. The commercial software ABAQUS is used to establish the finite element model of the small punch specimen with U-shaped notch. The local mechanical property parameters of TC4 titanium alloy under the three dimensional state of stress with tensile stress are obtained by combining finite element method. Meanwhile, the variation rule of Mises stress and void volume fraction (VVF) are analyzed. The test results show that the equivalent stress on the notch tip of the specimen increases with the constant pressure of the punch, reaching the peak stress of 1 150 MPa, and the VVF at the notch tip also increases to the critical VVF, finally resulting in the fracture failure. On the upper surface of the specimen, the VVF is lower. With the further pressing of the punch, the equivalent stress on the notch tip decreases gradually, while VVF show higher on the notch tip region and the edge region of the punch. When the peak load is reached, the stress triaxiality along path dropped from 2.28 to -0.64. It can be seen from the results that the void volume fraction at the notch root area is higher. And the distribution trend of stress triaxiality and void volume fraction of the path did not show significant change.

Key words: TC4 titanium alloy, small punch test, local mechanical heterogeneity, U-shaped notch, finite element method

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