| 摘要: |
| 以Ⅲ型裂纹(反平面剪切)问题为例，对裂纹尖端弹塑性应力场进行了分析研究。首先，基于断裂力学基本理论，引入弹塑性本构关系，推导弹塑性裂纹尖端场；其次，依据线弹性场中应力强度因子的定义和基于J-积分的弹塑性裂纹尖端应力场的分布，并结合物理意义，定义了与线弹性场应力强度因子一致的弹塑性应力强度因子，来表征弹塑性裂纹尖端应力场的强度；最后，对本文所定义的弹塑性应力强度因子进行了合理性分析，说明了本文定义的适用性。本文所定义的弹塑性应力强度因子，相比于表征弹塑性场的J-积分，具有更明确的物理意义和更简明的表达形式；为弹塑性裂纹尖端场的分析和含裂纹材料弹塑性破坏判据的建立提供了理论方法。另外，本文方式也适合于定义Ⅰ型和Ⅱ型问题。 |
| 关键词: 断裂力学 弹塑性本构 裂纹尖端场 应力强度因子 |
| DOI： |
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| 基金项目:国家高技术研究发展计划（2015AA034401） |
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| Characterization of Elastic-Plastic Stress Intensity Factor Based on Dimensional Analysis |
| ZHANG Zheng,LI Zeshang,WANG Yibing |
| (School of Aeronautic Science and Engineering, Beihang University, Beijing 100191, China) |
| Abstract: |
| Based on Ⅲ mode crack (anti-plane shear) problem, this paper presented that (1) derivation of solution for elastic-plastic crack-tip field, according to the methodology of facture mechanics, through generally elastic-plastic constitutive relations of materials; (2) definition of elastic-plastic stress intensity factor representing the singularity of elastic-plastic crack-tip field, combined with physical meaning, consistent with the stress intensity factor for linear elastic crack-tip field and referring to J-integral dominated elastic-plastic crack-tip field, to characterize the intensity of the stress in the elastic-plastic crack-tip field; (3) explanation of reasonability for this definition and the applicability of this definition. Compared with the common concept of J-integral, the elastic-plastic stress intensity factor defined in this paper demonstrates more illustrative physical meaning and more simple expression. This work also provided the theoretical fundamental for establishment of crack criterion. Additionally, the style of elastic-plastic stress intensity factor will be also suitable for Ⅰ-mode and Ⅱ-mode crack. |
| Key words: Fracture mechanics Elastoplastic constitutive Crack-tip field Stress intensity factor |