Seminar khoa học về chủ đề "Phương pháp tính toán nâng cao cho cơ học vỏ và rắn"

Vào 15h00, ngày 28/11/2025 Viện IAST tổ chức buổi trao đổi học thuật tại Phòng họp dưới khán đài A với nội dung chi tiết như sau:

Giáo sư Le Khanh Chau  báo cáo về chủ đề:  Asymptotically accurate and geometric locking-free finite element implementation of a refined shell theory.
Abstract: Accurate finite element analysis of refined shell theories is crucial but often hindered by membrane and shear locking effects. While various element-based locking-free techniques exist, this work addresses the problem at the theoretical level by utilizing results from asymptotic analysis. A formulation of a 2D refined shell theory incorporating transverse shear is developed using rescaled coordinates and angles of rotation, ensuring equal asymptotic orders of magnitude for extension, bending, and rotation measures and their respective stiffnesses. This novel approach, implemented via isogeometric analysis, is shown to be both asymptotically accurate relative to the underlying refined shell theory and inherently free from membrane and shear locking. Numerical simulations of semi-cylindrical shells show excellent agreement between the analytical solutions, 2D refined shell theory predictions, and 3D elasticity theory, validating the effectiveness and accuracy of the proposed formulation.

Tiến sĩ Bùi Hoàng Giang báo cáo về chủ đề: A modelling and analysis platform for solid mechanics

Abstract: In this talk, a modelling and analysis platform for solid mechanics is presented. Aiming at solving coupled problems involving strong interactions and nonlinear behavior, this computational software has solved complex problems in structural and geotechnical engineering. On the macro scale, the platform supports various advanced numerical methods, such as Isogeometric Analysis, CutFEM and Adaptive Mesh Refinement. At the micro scale, high fidelity constitutive laws, coupled with robust sub-stepping algorithm are implemented. The accuracy and convergence behavior of the material laws is further enhanced by nonlocal regularization via a gradient theory. In terms of usability, the software is equipped with a versatile post-processing module, and direct connection with Python scripting for model tuning and manipulation. Recently, this tool has been used to develop highly accurate plate and shell elements based on first-order asymptotic theory. Selected examples and use cases are presented to demonstrate the simulation capacity of the software.