PSI - Issue 70

Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 70 (2025) 105–112

Structural Integrity and Interactions of Materials in Civil Engineering Structures (SIIMCES-2025) Bending and buckling analysis of composites and sandwich plates: A novel higher-order zigzag theory

Aamir Anwar Nezami a * , Shaikh Jahangir Hossain a a Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur, India

Abstract Laminated composite plates are widely used in aerospace, automotive, marine, and civil engineering due to their high strength-to weight ratio and customizable mechanical properties. These plates, composed of fiber-reinforced layers bonded with polymer adhesives, exhibit complex deformation behaviour under mechanical, thermal, and environmental loads. Interlaminar weakness due to low-strength adhesives often leads to delamination and transverse cracking, necessitating precise predictions of interlaminar stresses and strains for accurate failure analysis. A key challenge in analyzing laminated composites is the zigzag effect, caused by significant shear deformation and discontinuities at layer interfaces. Understanding anisotropic elasticity, homogenization techniques, structural theories, and computational methods is essential for accurate modelling. Additionally, buckling behaviour is a critical failure mode, especially in lightweight composite structures subjected to compressive loads. Reliable prediction of buckling and post-buckling responses is crucial for designing efficient multi-layered composite and sandwich plates. This study introduces a comprehensive framework based on a novel zigzag theory for analyzing deformation, stress distributions, and buckling in laminated composites and sandwich plates. The theory's effectiveness is demonstrated through numerical examples encompassing various stacking sequences (cross-ply and angle-ply) and loading scenarios (bending and buckling). Comparisons with CLPT, FSDT, TSDT, and existing zigzag theories highlight the advantages of the proposed approach for accurate and efficient prediction of structural behaviour, leading to improved design of composite structures. The results obtained by the proposed novel zigzag theory are very close to Exact three-dimensional elasticity solutions.

© 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of International Conference on Structural Integrity Organizers

Keywords: Laminate; Sandwich; Zigzag; buckling; bending

* Aamir Anwar Nezami, Mob.: +91-9205493956. E-mail address: aamir.anwar47@gmail.com

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of International Conference on Structural Integrity Organizers 10.1016/j.prostr.2025.07.032