...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Computer Methods in Applied Mechanics and Engineering >Isogeometric enriched field approximations
【24h】

Isogeometric enriched field approximations

机译：等几何富集场近似

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Boundaries with specified behavior, phase boundaries, crack surfaces or singular points are, geometrically speaking, lower-dimensional features relative to two- or three-dimensional geometrical domains. Often, the distinguishing characteristics of the behavior at these features are known a priori and may be exploited to enrich isogeometric models. Explicit geometrical representations possess parametrically computable tangents, normals and curvature, while in implicit strategies, the geometric "exactness" of enriching lower-dimensional features is not exploited or retrieved only in the limit of mesh refinement. In the present work, CAD-inspired hierarchical partition of unity field compositions are extended to modeling explicitly defined enrichments within the isogeometric framework. The base approximations are "enriched" isogeometrically on parametrically defined lower-dimensional geometrical features of the base entity and by constructing distance fields from them. The efficiency and robustness of distance computations is significantly improved by composing monotonic distance measures, defined piecewise on the enriching geometric entity, using R-Functions. The procedure allows both the behavioral approximation as well as the material description to be enriched enabling the modeling of material damage (or, alternatively, local stiffening). Further, the enrichments may ensure known function value or its derivative. Function value enrichments are demonstrated to model Dirichlet boundary conditions and propagating cracks. The derivative enrichments are used to model Neumann boundary conditions as well as strain jumps across material interfaces. The material enrichments are demonstrated through the use of a cohesive damage law to model arbitrary crack initiation and propagation within the domain.
机译：从几何学上来说，具有指定行为，相边界，裂纹表面或奇异点的边界是相对于二维或三维几何域的低维特征。通常，在这些特征处的行为的区别特征是先验的，可以用来丰富等几何模型。显式的几何表示具有可参数计算的切线，法线和曲率，而在隐式策略中，仅在网格细化的范围内不能利用或检索丰富低维特征的几何“精确性”。在本工作中，受CAD启发的统一场组成的分层划分扩展为对等几何框架内明确定义的富集建模。基本近似值在参数定义的基本实体的较低维几何特征上等距几何化并通过从它们构造距离场来“丰富”。通过使用R函数组成在富集几何实体上分段定义的单调距离度量，可以大大提高距离计算的效率和鲁棒性。该程序可以丰富行为近似以及材料描述，从而可以对材料损坏（或局部硬化）进行建模。此外，富集可以确保已知功能值或其导数。证明了函数值富集可以模拟Dirichlet边界条件和扩展裂纹。导数富集用于建模Neumann边界条件以及材料界面上的应变跳跃。通过使用内聚破坏定律模拟在区域内任意裂纹的萌生和扩展，可以证明材料的富集。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号