Stability analysis of thick laminated anisotropic plate using third order energy functional
Date
2024-08
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Publisher
Federal University of Technology, Owerri
Abstract
TheStability Analysis of Thick Laminated Anisotropic Plate using Third Order Energy Functional is presented. Fourteen different boundary conditions were considered in this research work thus SSSS, CCCC, SSCC, CCSS, CSSS, SSSC, SCSC, CSCS, SSSC, CCCS, CSSC, SCCS, CCSC and SSCS. The shape functions for all the fourteen plates were derived by considering the deflection and second derivative of deflection at the simple support edge while the deflection and first derivative of deflection were considered at the clamped support. The integral values of the differentiated shape functions, (𝐾̅ − 𝑣𝑎𝑙𝑢𝑒𝑠 )of the various boundary conditions were obtained. From these, the stiffness coefficients, ki of the various boundary conditions were generated. Resolving from the first principle and by considering the relationship between the in-plane displacement and out of plane displacement, the strain and the stress functions for thick laminated laminated plate were obtained. The total potential energy was formulated by adding the work done by external load to the strain energy equation. Differentiating the total potential energy with respect to the deflection w, gave rise to the governing equation. Four compatible equations were formulated also by differentiating the total potential equation with respect to the two middle-layer in-plane displacements, (–uo and - vo) and two shear rotations, (∅xand ∅y).. Numerical analysis for the different plate laminas were conducted, considering different angles of arrangement The third order stiffnesses were formulated for thick laminated anisotropic plate and the results from this present work were compared with those from Ventsel & Krauthermmer (2001) The comparison showed acceptable percentage difference of 0.01% & 2% level of significance in statistics. The derived buckling loads for all the plates studied in this work, were compared with those from Reddy, Megson and Chajes (Previous Researchers) and the percentage differences obtained were within the range of 0.01% to 0.9%.. It is concluded that this method can be adopted in solving a laminated thick anisotropic plate using 3rd order energy functional.
Description
This thesis is for the award of Doctor of Philosophy (PhD.) in Structural Engineering
Keywords
Boundary condition, stability analysis, critical buckling load, polynomial series, third order strain energy, shape functions, third order energy functional, Department of Civil Engineering
Citation
Uzoukwu, S. C. (2024). Stability analysis of thick laminated anisotropic plate using third order energy functional (Unpublished Doctoral Thesis). Federal University of Technology, Owerri, Nigeria