Dynamic stationary crack analysis of isotropic solids and anisotropic composites by enhanced local enriched consecutive-interpolation elements
Dynamic stationary crack analysis of isotropic solids and anisotropic composites by enhanced local enriched consecutive-interpolation elements
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DOI：
10.1016/j.compstruct.2017.08.021
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发表时间：
2017-11
影响因子：
6.3
通讯作者：
Zuoyi Kang;T. Bui;D. Nguyen;S. Hirose
中科院分区：
文献类型：
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作者：
Zuoyi Kang;T. Bui;D. Nguyen;S. Hirose
将新近发展起来的局部强化连续插值四节点四边形单元(XCQ4)推广到各向同性固体和含静止裂纹的各向异性复合材料的暂态动态应力强度因子。XCQ4使用节点值和平均节点梯度作为内插条件，以平滑未知变量的分布。将连续内插法(CIP)中可能存在的节点物理性质视为非局部性特征，提高了计算结果的精度，消除了单元间的非光滑应力。在XCQ4中，裂纹由Level Set函数确定，并由Heaviside富集函数和具有特殊各向异性富集型裂尖函数的裂尖富集函数进行富集化。用Newmark时间积分格式在每个时间步长上求解动态裂纹的时变离散方程，不考虑基于速度的全局阻尼阵的影响。通过一系列各向同性和各向异性材料瞬时断裂的数值算例，验证了该方法的有效性。数值模拟结果与文献中提供的参考解进行了比较。探讨了复杂结构试件在阶跃荷载和正弦荷载作用下的动力响应行为。
The recently developed local enriched consecutive-interpolation 4-node quadrilateral element (XCQ4) is extended to study transient dynamic stress intensity factors (DSIFs) for isotropic solids and anisotropic composite materials containing stationary cracks. The XCQ4 involves both nodal values and averaged nodal gradients as interpolation conditions to smooth the distribution of unknown variables. The possible physical properties of enriched nodes in consecutive-interpolation procedure (CIP) would be thought as non-locality feature, which could improve the accuracy of results and eliminate the non-smooth stresses among inter-elements. In XCQ4, the crack is determined by level set function and enriched by Heaviside and crack-tip enrichment functions with special anisotropic enriched crack-tip functions. Time-dependent discrete equations for dynamic cracks are solved by Newmark time integration scheme at each time step without considering the effects of velocity-based global damping matrix. The proposed method is verified through a series of numerical examples of transient fracture in both isotropic and anisotropic materials. Numerical DSIFs are compared with reference solutions available in literature. The behavior of dynamic response is explored in specimens with complex configuration under step and sine loads.