DOMAIN-BOUNDARY ELEMENT METHOD FOR ELASTODYNAMICS OF FUNCTIONALLY GRADED THICK-WALLED CYLINDERS AND ANNULLAR COATINGS

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Abdelrahim Abeidi - PhD thesis.pdf

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2022-12-16

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Abeidi, Abdelrahim

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In this thesis, a new computational technique using domain boundary element method (D-BEM) will be developed to perform the elastodynamic analysis of functionally graded thick-walled cylinders and annular coatings. The thick-walled cylinder material properties are varying along the radial direction according to a power distribution law of volume fraction; hence, the cylinder can withstand pressure shock types of loadings. These mechanical loads are described by uniform dynamic pressures at the inner and outer edges. Therefore, the FGM thick-walled cylinder is subjected to axisymmetric external loading in plane strain condition. The domain boundary element method will be implemented to solve the integral equations achieved by using the static fundamental solution to write the governing differential equation in the residual form. However, since the problem is dynamic, time dependent, isoparametric quadrilateral elements will be proposed to discretize the domain. The integral equations will be computed for each element and a system of time dependent ordinary differential equations will result. The time response is obtained by using Houbolt method of time marching scheme to solve the system of ordinary differential equations. Therefore, the proposed D-BEM method is verified by considering various researches, which study the elastodynamics of FGM thick-walled cylinders subjected to different mechanical loadings on the inner surface, such as: mechanical shock and exponential loadings. Furthermore, the FGM thick-walled cylinder elastodynamic response has been studied using the D-BEM in plane stress and plane strain conditions. An internal and external ramp dynamic pressure and an internal exponential dynamic pressure are considered in the study of the composite thick-walled cylinders and annular coatings. The radial displacement response, radial and hoop stresses are calculated at different material property gradation values. Moreover, for the pressure shock loadings selected, the spatial radial displacement, spatial radial and hoop stresses are studied.

Subject Keywords

Thick-Walled Cylinder, Annular Coatings, FGM, Elastodynamic, D-BEM

URI

https://hdl.handle.net/11511/101781

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

A. Abeidi, “DOMAIN-BOUNDARY ELEMENT METHOD FOR ELASTODYNAMICS OF FUNCTIONALLY GRADED THICK-WALLED CYLINDERS AND ANNULLAR COATINGS,” Ph.D. - Doctoral Program, Middle East Technical University, 2022.