西南石油大学学报(自然科学版) ›› 2021, Vol. 43 ›› Issue (6): 42-53.DOI: 10.11885/j.issn.1674-5086.2020.10.05.03

• 力学专刊 • 上一篇    下一篇

基于广义最大周向应变准则的断裂特性研究

华文, 潘鑫, 淦志强, 董世明   

  1. 深地科学与工程教育部重点实验室·四川大学, 四川 成都 610065
  • 收稿日期:2020-10-05 发布日期:2022-01-08
  • 通讯作者: 董世明,E-mail:smdong@scu.edu.cn
  • 作者简介:华文,1989年生,男,汉族,四川宜宾人,助理研究员,博士后,主要从事岩石力学、断裂力学等方面的研究工作。E-mail:wenhua@scu.edu.cn;潘鑫,1993年生,男,汉族,四川达州人,博士研究生,主要从事断裂力学方面的研究工作。E-mail:pan-px@foxmail.com;淦志强,1998年生,男,汉族,江西九江人,硕士研究生,主要从事岩石断裂等方面的研究工作。Email:1776076714@qq.com;董世明,1963年生,男,汉族,河南信阳人,教授,博士,主要从事岩石断裂方面的研究工作。E-mail:smdong@scu.edu.cn
  • 基金资助:
    国家自然科学基金(11872042);四川省科技厅应用基础研究项目((2018JY0024、2019YJ0156、2021YJ0357);中国博士后科学基金(2019M653395)

A Study on the Fracture Characteristics Analysis Based on the Generalized Maximum Tangential Strain Criterion

HUA Wen, PAN Xin, GAN Zhiqing, DONG Shiming   

  1. MOE Key Laboratory of Deep Underground Science and Engineering, Sichuan University, Chengdu, Sichuan 610065, China
  • Received:2020-10-05 Published:2022-01-08

摘要: 裂纹尖端应力场的非奇异性常数项(T应力)对脆性或准脆性材料的断裂特性及裂尖塑性区的形状和大小都有显著的影响。为了探究T应力对脆性或准脆性材料I~II复合型断裂特性的影响规律,基于先前研究中提出的计及T应力影响的广义最大周向应变准则进一步讨论了T应力、裂纹尖端的临界距离r0和泊松比ν对中心裂纹圆盘试件的裂纹扩展路径以及临界应力强度因子的影响规律,并利用该准则对基于中心裂纹圆盘试件的断裂试验结果进行了有效评估。结果表明:与传统的最大周向应变准则相比,中心裂纹圆盘试件中由于负T应力的存在,会使得裂纹开裂角的绝对值减小,同时使得临界应力强度因子(断裂韧度)的值增加。考虑了T应力影响的广义最大周向应变准则能很好的对试验结果进行预测;并且在纯II型时,基于广义最大周向应变准则的理论预测值比基于广义最大周向应力准则的理论预测值更接近试验值。

关键词: I~II复合型断裂, 断裂韧度, T应力, 广义最大周向应变准则, 中心裂纹圆盘

Abstract: The non-singular constant stress term (T-stress) around the crack tip remarkably affects the fracture characteristics of brittle or quasi-brittle materials, and it is also closely related to the shape and size of the plastic zone near the crack tip. In order to explore the influence of T-stress on the I~II mixed mode fracture characteristics of brittle or quasi-brittle materials, the generalized maximum tangential strain (GMTSN) criterion, which considers the effect of T-stress, has been proposed in our previous research. In this paper, the further study on the effects of T-stress, critical distance r0 and Poisson's ratio ν on the crack propagation path and the fracture resistance for central cracked Brazilian disc (CCBD) specimens have been carried out according to the GMTSN criterion. Moreover, the GMTSN criterion is used to predict the test results obtained with CCBD specimens. The results indicate that the T-stress and Poisson's ratio have a remarkable influence on the mixed mode fracture resistance based on the GMTSN criterion. When compared with the traditional maximum tangential strain (MTSN) criterion, a negative T-stress in a CCBD specimen always decreases the absolute value of the fracture initiation angle; however, the value of critical stress intensity factor is increased for negative values of T-stress. Theoretical values based on the GMTSN criterion, which considers the effect of T-stress, are in very good agreement with the test results. Moreover, the GMTSN criterion provides a better prediction for pure mode II when compared with the generalized maximum tangential stress (GMTS) criterion.

Key words: I~II mixed mode fracture, fracture toughness, T-stress, generalized maximum tangential strain criterion, central cracked Brazilian disc

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