Abstract:
In this presentation, a semi-analytical model based on a mixed variational principle and the Rayleigh-Ritz method is developed for the buckling and post-buckling analysis of variable stiffness composite laminates. The variational functional form is expressed using Airy’s stress function and out-of-plane plate deflection and the minimization of the functional resulted in coupled non-linear algebraic equations which were solved using a Newton-Raphson algorithm. The generality of the proposed formulation allows modelling of the pure/ mixed stress in-plane boundary conditions effectively and provides a computationally efficient way to determine the critical buckling load and the post-buckling strength of variable stiffness composite plates. The proposed methodology is applied to solve the buckling and post-buckling problems of variable stiffness composite plates under uniform edge displacement/force boundary conditions. Based on this semi-analytical model, the optimum variable stiffness composite laminates for post-buckling are determined using the genetic algorithm (GA). The optimisation results for the variable stiffness laminates demonstrated their substantial improved load-carrying capability subjected to a given end-shortening strain or a maximum transverse deflection in the post-buckling regime compared with the constant stiffness laminates. Finally, the post-buckling solutions of the optimum variable stiffness laminates are validated by finite element method.
Bio:
Dr. Wu Zhangming received his Ph.D. from Aston University, UK. He is currently a Senior lecturer at Cardiff University. He has published more than 60 papers in the fields of structural mechanics (buckling, post-buckling, vibration), modelling (Rayleigh-Ritz method), and optimization (Citations:1753, h-index: 21), won the Best Paper Award of the AIAA twice, and authorized a number of innovation patents. Dr. Wu has been invited to give reports at international academic conferences (International Conference on Composite Materials Structure ICCS, International Computational Mechanics Conference WCCM, China International Composite Materials Technology Conference, etc.) and served as the chairman of the branch (International Conference on Composite Materials, International Conference on Computational Mechanics, etc.) and organize academic conference sub-venues (WCCM13 Buckling and Post-buckling Symposium). Dr. Wu has been invited to make academic reports at famous universities and academic institutions at home and abroad, such as Shanghai Jiaotong University, Swansea University, Beihang University. Participated in and presided over a number of scientific research projects in the UK and China; reviewers for international journals such as Composite Structures, International Journal of Solids and Structures, Thin-Walled Structures, AIAA Journal, Composite Science Technology; AIAA Journal.
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Time: 14:00 pm