Work

Nonlinear elastodynamic material identification of heterogeneous isogeometric Bernoulli–Euler beams

Year: 2025

Type: article

Abstract: This paper presents a Finite Element Model Updating framework for identifying heterogeneous material distributions in planar Bernoulli–Euler beams based on a rotation-free isogeometric formulation. The procedure follows two steps: First, the elastic properties are identified from quasi-static displacements; then, the density is determined from modal data (low frequencies and mode shapes), given the previously obtained elastic properties. The identification relies on three independent discretizations: the isogeometric finite element mesh, a high-resolution grid of experimental measurements, and a material mesh composed of low-order Lagrange elements. The material mesh approximates the unknown material distributions, with its nodal values serving as design variables. The error between experiments and numerical model is expressed in a least-squares manner. The objective is minimized using local optimization with the trust-region method, providing analytical derivatives to accelerate computations. Several numerical examples exhibiting large displacements are provided to test the proposed approach. To alleviate membrane locking, a hybrid discretization approach is employed when necessary. Quasi-experimental data are generated using refined finite element models with random noise applied up to 4 %. The method yields satisfactory results as long as a sufficient amount of experimental data is available, even for high measurement noise. Regularization is used to ensure a stable solution for dense material meshes. The density can be accurately reconstructed based on the previously identified elastic properties. The proposed framework can be straightforwardly extended to shells and 3D continua.

Source: Computer Methods in Applied Mechanics and Engineering

DOI: 10.1016/j.cma.2025.118415

Authors: Bartłomiej Łazorczyk, Roger A. Sauer

Institutions: Gdańsk University of Technology, Indian Institute of Technology Guwahati, Ruhr University Bochum

Language: English

Topic: Advanced Numerical Analysis Techniques

Subfield: Computational Mechanics

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,830

Funder: Politechnika Gdańska