Sophisticated computational techniques for damage mechanics with mixed uncertain input fields

具有混合不确定输入场的损伤力学的复杂计算技术

• 批准号: 341840349
• 负责人: Professor Dr.-Ing. Udo Nackenhorst
• 金额: --
• 依托单位: Institut für Baumechanik und Numerische Mechanik (IBNM)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/341840349?language=en
• 关键词: Sophisticated; computational; techniques; damage; mechanics

Goal of this research project is to provide efficient computational techniques for detailed damage mechanics finite element models with uncertain input variables. For the treatment of epistemic uncertainties, i.e. unknown input random field parameters, a Dempster-Shafer p-box approach will be utilized and implemented into an adaptive nested sampling strategy. Systematic studies on the discretization of pboxesin dependency on the input field modeling approach, alternatively via Karhunen-Loeve expansion (KLE) or Polynomial Chaos expansion (PCE) will be investigated. An adaptive multi-level Monte-Carlo scheme will be applied for an efficient sampling of the structural response surfaces. This scheme has to be extended for the nested epistemic-aleatory sampling defining some sophisticated error criteria. With emphasis to sensitivity or reliability analysis response surfaces for the quantities of interest, i.e. remaining load bearing capacity, will be generated. Here an adaptive generalized Polynomial Chaos(gPC) scheme will be implemented, where for the epistemic parameter space newer developments on elementwise gPC appears an attractive option. Systematic studies on the efficient and accurate construction of possibly element-wise orthogonal polynomials have to be performed. The applicability of the developed computational approach will be studied on our own 3-dimensional bench-mark problem on a concrete beam subjected to 4 point bending loads. This example serves for parametric studies of the overall computational approach.

本研究项目的目的是为具有不确定输入变量的详细损伤力学有限元模型提供有效的计算方法。对于认知不确定性的处理，即未知的输入随机场参数，将利用Dempster-Shafer p-box方法并将其实施为自适应嵌套抽样策略。系统地研究了Pboxesin依赖于输入场建模方法的离散化，或者是通过Karhunen-Love展开(KLE)或多项式混沌展开(PCE)。采用自适应多层蒙特卡罗方法对结构响应面进行有效抽样。对于定义了一些复杂误差标准的嵌套认知-情感抽样，必须将该方案扩展。在强调灵敏度或可靠性分析时，将生成感兴趣的数量的响应面，即剩余承载能力。这里将实现一种自适应广义多项式混沌(GPC)方案，其中对于认知参数空间，基于元素的广义多项式混沌的新发展似乎是一个有吸引力的选择。对于可能的元素级正交多项式的有效和精确的构造，必须进行系统的研究。我们将用我们自己的混凝土梁在四点弯曲荷载作用下的三维基准问题来研究所发展的计算方法的适用性。此示例用于整体计算方法的参数研究。