Extended Voronoi cell finite element model for multiple cohesive crack propagation in brittle materials
Extended Voronoi cell finite element model for multiple cohesive crack propagation in brittle materials
复制标题
DOI：
10.1002/nme.1472
复制
发表时间：
2006-02
影响因子：
2.9
通讯作者：
Shanhu Li;Somnath Ghosh
中科院分区：
文献类型：
--
作者：
Shanhu Li;Somnath Ghosh
本文介绍了一种扩展的Voronoi单元有限元模型（X - VCFEM），用于模拟具有多个裂纹的脆性材料的内聚裂纹扩展。裂纹的增量方向和扩展长度由裂纹尖端附近的黏聚能决定。扩展到VCFEM是通过增强假定的应力混合公式中的应力函数来实现的。除了多项式项外，应力函数还包括与水平集方法相结合的分支函数，以及裂纹尖端附近的多分辨率小波函数。小波基函数自适应丰富，以准确捕获裂纹尖端应力集中。在X - VCFEM中采用稳定性条件和方法来改善裂纹扩展时的收敛性。本文解决了两类问题，并与文献中已有的解决方案进行了比较，以验证X‐VCFEM算法的有效性。前一组对应于静态裂纹的结果，后一组则考虑了内聚裂纹的扩展。将X - VCFEM模拟结果与文献结果进行了比较，验证了X - VCFEM的有效性。版权所有©2005 John Wiley & Sons， Ltd
This paper introduces an extended Voronoi cell finite‐element model (X‐VCFEM) for modelling cohesive crack propagation in brittle materials with multiple cracks. The cracks are modelled by a cohesive zone model and their incremental directions and growth lengths are determined in terms of the cohesive energy near the crack tip. Extension to VCFEM is achieved through enhancements in stress functions in the assumed stress hybrid formulation. In addition to polynomial terms, the stress functions include branch functions in conjunction with level set methods, and multi‐resolution wavelet functions in the vicinity of crack tips. The wavelet basis functions are adaptively enriched to accurately capture crack‐tip stress concentrations. Conditions and methods of stability are enforced in X‐VCFEM for improved convergence with propagating cracks. Two classes of problems are solved and compared with existing solutions in the literature for validation of the X‐VCFEM algorithms. The first set corresponds to results for static cracks, while in the latter set, the propagation of cohesive cracks are considered. Comparison of X‐VCFEM simulation results with results in literature for several fracture mechanics problems validates the effectiveness of X‐VCFEM. Copyright © 2005 John Wiley & Sons, Ltd.