论文标题

参数射击随机盖素混合近似于线性毛弹性和不确定输入的近似值

Parameter-robust Stochastic Galerkin mixed approximation for linear poroelasticity with uncertain inputs

论文作者

Khan, Arbaz, Powell, Catherine E.

论文摘要

线性毛弹性模型在生物学和地球物理中具有许多重要的应用。特别是,Biot的合并模型是一个众所周知的模型,它描述了多孔弹性培养基的线性响应与其中的扩散流体流之间的耦合相互作用,假设存在较小的变形。尽管对确定性的线性孔隙弹性模型和有限元元素方法进行了很好的研究,但迄今为止,在鲁棒算法上,几乎没有工作,用于求解具有不确定输入和执行不确定性定量(UQ)(UQ)的毛弹性模型。 Biot模型具有许多重要的物理参数和输入,在现实世界中,其精确值通常不确定。在这项工作中,我们介绍和分析了一个新的五场模型的适当性,该模型具有不确定的和空间变化的杨氏模量和液压电导率场。通过使用适当加权的规范,我们确定弱解决方案在关键物理参数(包括泊松比)的变化方面是稳定的。然后,我们引入了一种新颖的无锁定随机盖勒金混合有限元方法,该方法在不可压缩的极限下具有鲁棒性。我们由“右”规范武装,为相关的离散系统构建了一个参数式预处理。我们的新方法促进了向前的UQ,可以有效地计算统计量的关注数量,并且证明在泊松比的变化,Biot-Willis常数和存储系数以及离散参数方面非常强大。

Linear poroelasticity models have a number of important applications in biology and geophysics. In particular, Biot's consolidation model is a well-known model that describes the coupled interaction between the linear response of a porous elastic medium and a diffusive fluid flow within it, assuming small deformations. Although deterministic linear poroelasticity models and finite element methods for solving them numerically have been well studied, there is little work to date on robust algorithms for solving poroelasticity models with uncertain inputs and for performing uncertainty quantification (UQ). The Biot model has a number of important physical parameters and inputs whose precise values are often uncertain in real world scenarios. In this work, we introduce and analyse the well-posedness of a new five-field model with uncertain and spatially varying Young's modulus and hydraulic conductivity field. By working with a properly weighted norm, we establish that the weak solution is stable with respect to variations in key physical parameters, including the Poisson ratio. We then introduce a novel locking-free stochastic Galerkin mixed finite element method that is robust in the incompressible limit. Armed with the `right' norm, we construct a parameter-robust preconditioner for the associated discrete systems. Our new method facilitates forward UQ, allowing efficient calculation of statistical quantities of interest and is provably robust with respect to variations in the Poisson ratio, the Biot--Willis constant and the storage coefficient, as well as the discretization parameters.

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