| 吴智敏,董伟,许青.混凝土Ⅰ-Ⅱ复合型裂缝扩展准则及扩展全过程的数值模拟[J].水利学报,2009,40(2): |
| 混凝土Ⅰ-Ⅱ复合型裂缝扩展准则及扩展全过程的数值模拟 |
| Propagation criterion for mixed mode Ⅰ-Ⅱ crack propagation and numerical simulation of the whole propagation process |
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| DOI： |
| 中文关键词: 混凝土 Ⅰ-Ⅱ复合型裂缝 有限元 扩展准则 数值模拟 |
| 英文关键词: concrete mixed mode Ⅰ-Ⅱ fracture FEM crack propagation criterion numerical simulation |
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| 中文摘要: |
| 本文基于从试验中得出的混凝土Ⅰ-Ⅱ复合型裂缝起裂时的临界KⅠ-KⅡ曲线，提出了Ⅰ-Ⅱ复合型裂缝的扩展准则，即由外荷载在裂缝尖端产生的应力强度因子与虚拟裂缝黏聚力产生的应力强度因子的差大于或等于起裂时的临界KⅠ-KⅡ曲线时裂缝扩展，在此基础上采用有限元法对混凝土Ⅰ-Ⅱ复合型裂缝的起裂、稳定扩展及失稳扩展全过程进行了数值模拟，并计算了试件高度分别为200、300、400、500、600mm混凝土四点剪切梁的裂缝扩展路径、荷载-剪切位移曲线，数值模拟结果与试验结果吻合良好。研究表明，只要从试验中测得混凝土材料的Ⅰ-Ⅱ复合型裂缝起裂时的临界KⅠ-KⅡ曲线、抗拉强度及弹性模量，即可计算混凝土Ⅰ-Ⅱ复合型裂缝扩展全过程。 |
| 英文摘要: |
| A crack propagation criterion for mixed mode Ⅰ-Ⅱ fracture in concrete based on the initial crackingKⅠ-KⅡ curve, obtained from experiment, is proposed. It defines that the propagation of crack begins when the difference between the stress intensity factor at the crack tip caused by the external load and the stress intensity factor caused by the virtue cohesive force is equal to or higher than the criticalKⅠ-KⅡ curve. On this basis, the FEM is applied to numerically simulate the whole process of initiation, stable propagation and unstable failure of mixed mode Ⅰ-Ⅱ crack in concrete. The crack propagation trajectories and the relationship between load and shear displacement of crack (P-CMSD) for specimens with height 200mm, 300mm, 400mm and 500mm are calculated respectively. The results well agree with experimental data. It may concluded that if the criticalKⅠ-KⅡcurve, uniaxial tensile strength and elastic modulus are measured the whole process of mixed mode Ⅰ-Ⅱ fracture can be simulated by using the proposed criterion. |
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