Investigation of buckling, post-buckling behaviour of variable stiffness composite plates

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2022-8-31

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Cömert, Utku Kaan

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In this thesis, buckling and post-buckling behaviour of variable stiffness (VS) composite plates are investigated. VS plates are designed by using quadratic Bezier curves to define fiber paths and a script is written for this purpose. Manufacturing limitations and defects are included into the simulations. In the analyses, Finite Element Method (FEM) is used to solve linear and nonlinear buckling with Hashin failure criterion. The plates constructed by using fiber paths with linear and nonlinear angle variation are simulated and the method is validated with tests from literature. Optimization cycles are run to optimize the buckling load of variable stiffness plates with a central hole for different plates. Post-buckling behaviour of plates with optimum angle configurations are investigated by considering progressive failure. It is observed that nonlinear angle variation can enlarge the design space and improve buckling load. For the first ply failure loads, an improvement is also observed for plates with quadratic Bezier curve fiber paths.

Subject Keywords

Variable stiffness, Bezier, Buckling, Post-buckling, Progressive failure

URI

https://hdl.handle.net/11511/99392

Collections

Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

U. K. Cömert, “Investigation of buckling, post-buckling behaviour of variable stiffness composite plates,” M.S. - Master of Science, Middle East Technical University, 2022.