A Novel Virtual Node Method for Polygonal Elements
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摘要: 虚节点法是一种新的基于单位分解理论的多边形有限元法.将虚节点法应用于求解弹性力学问题,并且通过大量数值实验测试虚节点法的计算效果.因为虚节点法具有多项式形式,所以有效地降低了传统多边形有限元法的积分误差.数值实验证明,在分片实验中虚节点法能得到比包括Wachspress法和mean value法在内的传统多边形有限元法更精确的数值结果.在收敛性试验中,虚节点法在相同节点数的条件下能取得比三角形一次单元更精确的数值结果.因为虚节点法能适应任意边数的多边形单元,所以对网格具有很强的适应性,在几何条件复杂、网格生成困难的问题中具有良好的应用价值.为了展示虚节点法潜在的应用价值,用虚节点法求解断裂力学应力强度因子和模拟裂纹扩展.同时,基于多边形单元的网格重划分技术和网格加密技术也应用于求解断裂力学应力强度因子和模拟裂纹扩展Abstract: A novel polygonal finite element method (PFEM), which is based on partition of unity, was proposed and named as virtual node method (VNM). To test the perform ance of present method, intensive numerical examples were carried out for solid mechanic problems. With polynomial form, virtual node method achieves better results than that of traditional PFEM, including Wachspress method and mean value method in standard patch test Compared with standard triangular FEM, virtual node method can achieve better accuracy. With the ability to construct shape function on polygonal elements, virtual node method provides greater flexibility in mesh generation. Therefore, several fracture problems were studied to demonstrate poten tialim plemen tation. With the advantage of virtual node method, convenien trefinement and remeshing strategy are applied.
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