基于有限断裂法和比例边界有限元法的裂纹扩展模拟

发布时间：2018-06-16 00:36

本文选题：有限断裂法 + 比例边界有限元　；参考：《计算力学学报》2017年02期

【摘要】：基于有限断裂法和比例边界有限元法提出了一种裂缝开裂过程模拟的数值模型。采用基于有限断裂法的混合断裂准则作为起裂及扩展的判断标准,当最大环向应力和能量释放率同时达到其临界值时,裂缝扩展。结合多边形比例边界有限元法,可以半解析地求解裂尖区域附近的应力场和位移场,在裂尖附近无需富集即可获得高精度的解。计算能量释放率时,只需将裂尖多边形内的裂尖位置局部调整,无需改变整体网格的分布,网格重剖分的工作量降至最少。裂缝扩展步长通过混合断裂准则确定,避免了人为假设的随意性,并可以实现裂缝变步长扩展的模拟,更符合实际情况。通过对四点剪切梁的复合型裂缝扩展过程的模拟,对本文模型进行了验证,并应用于重力坝模型的裂缝扩展模拟,计算结果表明,本文提出的模型简单易行且精度较高。
[Abstract]:Based on finite fracture method and proportional boundary finite element method, a numerical model for simulation of crack cracking process is presented. The mixed fracture criterion based on finite fracture method is used as the criterion of crack initiation and propagation. When the maximum circumferential stress and the energy release rate reach the critical value simultaneously, the crack propagation. Combined with the polygonal proportional boundary finite element method, the stress field and displacement field near the crack tip can be semi-analytically solved, and a high-precision solution can be obtained near the crack tip without enrichment. When calculating the energy release rate, we only need to adjust the crack tip position in the crack tip polygon, do not need to change the distribution of the whole mesh, and reduce the workload of mesh redivision to the minimum. The crack propagation step is determined by mixed fracture criterion, which avoids the randomness of artificial hypothesis, and can realize the simulation of crack variable step propagation, which is more in line with the actual situation. Through the simulation of the composite crack propagation process of the four-point shear beam, the model is verified and applied to the crack propagation simulation of the gravity dam model. The calculation results show that the proposed model is simple and accurate.
【作者单位】：大连理工大学建设工程学部;
【基金】：国家自然科学基金(51579033,51009019) 中央高校基本科研业务费专项(DUT14LK40) 中国博士后基金特别资助项目(2013T60283)资助
【分类号】：O302;O346.1

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