Robust Finite Element Schemes for Inhomogeneous Bi-Laplace Problems

核心概念

This paper presents lowest-degree robust finite element schemes for solving inhomogeneous bi-Laplace problems, including an inhomogeneous fourth-order elliptic singular perturbation problem and a Helmholtz transmission eigenvalue problem. The schemes use the reduced rectangle Morley (RRM) element space with piecewise quadratic polynomials, which are of the lowest degree possible.

要約

The paper focuses on developing efficient numerical methods for solving inhomogeneous bi-Laplace problems, which arise in various applications such as modeling thin buckling plates and Helmholtz transmission eigenvalue problems.

Key highlights:

1. The authors propose finite element schemes on rectangular grids using the reduced rectangle Morley (RRM) element space with piecewise quadratic polynomials. This is the lowest degree possible for such problems.

2. A discrete analogue of an equality by Grisvard is proved for the stability issue, and a locally-averaged interpolation operator is constructed for the approximation issue. This allows for optimal convergence rates of the schemes.

3. For an inhomogeneous fourth-order elliptic singular perturbation problem, a robust RRM scheme is developed that is stable and convergent independent of the perturbation parameter.

4. For the Helmholtz transmission eigenvalue problem, an optimal RRM scheme is presented that achieves optimal convergence rates.

5. Numerical experiments are provided to verify the theoretical analysis and demonstrate the effectiveness of the proposed schemes.

The paper presents a comprehensive study on developing lowest-degree robust finite element methods for solving challenging inhomogeneous bi-Laplace problems, with rigorous mathematical analysis and practical numerical validations.

統計

None.

引用

None.

抽出されたキーインサイト

Lowest-degree robust finite element schemes for inhomogeneous bi-Laplace problems

by Bin Dai,Huil... 場所 arxiv.org 04-23-2024

https://arxiv.org/pdf/2404.13676.pdf

深掘り質問

How can the proposed RRM element schemes be extended to three-dimensional or higher-dimensional inhomogeneous bi-Laplace problems

The extension of the proposed Reduced Rectangular Morley (RRM) element schemes to three-dimensional or higher-dimensional inhomogeneous bi-Laplace problems can be achieved by adapting the basis functions and interpolation techniques to the additional dimensions. In three dimensions, the RRM element space would consist of piecewise quadratic polynomials defined on tetrahedral or hexahedral elements instead of rectangles. The interpolation operators and stability analysis would need to be modified to account for the increased complexity and dimensionality of the problem. By extending the RRM element space to three or more dimensions, the schemes can be applied to inhomogeneous bi-Laplace problems in higher-dimensional spaces, providing a robust and efficient discretization method.

What are the potential limitations or challenges in applying the RRM element approach to more complex inhomogeneous bi-Laplace problems, such as those with multi-scale coefficients or irregular domains

Applying the RRM element approach to more complex inhomogeneous bi-Laplace problems, such as those with multi-scale coefficients or irregular domains, may present certain limitations and challenges. One potential limitation is the increased computational complexity associated with handling multi-scale coefficients, which may require adaptive mesh refinement strategies or specialized interpolation techniques to accurately capture the varying scales in the problem. Irregular domains can also pose challenges in terms of mesh generation and stability of the finite element schemes, as the RRM element space is designed for rectangular grids and may need to be adapted for non-rectangular domains. Additionally, the analysis and implementation of the RRM element approach may need to be refined to address the specific characteristics of these more complex problems, ensuring stability, accuracy, and efficiency in the numerical solution.

Beyond the two model problems considered, what other types of inhomogeneous bi-Laplace problems could benefit from the RRM element discretization, and how would the analysis and implementation need to be adapted

Beyond the fourth-order elliptic perturbation problem and the Helmholtz transmission eigenvalue problem considered in the study, the RRM element discretization could benefit a wide range of inhomogeneous bi-Laplace problems in various applications. Some examples include problems in structural mechanics, fluid dynamics, electromagnetics, and geophysics, where the bi-Laplace operator arises in the governing equations. These problems may involve heterogeneous materials, varying coefficients, or irregular geometries, making them suitable candidates for the robust and efficient RRM element schemes. To adapt the analysis and implementation for these different types of problems, the interpolation operators, stability analysis, and error estimates may need to be customized based on the specific characteristics and requirements of each problem, ensuring accurate and reliable numerical solutions.