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A large deformation analysis of elastoviscoplastic shells by finite element method | |
Author | Rao, Vakkalagadda Venkata Sreedhara |
Call Number | AIT Diss. no. ST-81-01 |
Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering, School of Engineering and Technology |
Publisher | Asian Institute of Technology |
Abstract | A total Lagrangian formulation for large deformation analysis of elasto-viscoplastic shells is presented. Shells are treated as special cases of continuum, i.e., thick shell assumptions are used to degenerate a bilinear quadrilateral shell element from a solid element. Total strain is taken as the sum of elastic and viscoplastic strains. The viscoplastic strain increments are computed by a rate law in conjunction with the isotropic von Mises yield criterion. Displacement field in the shell element is described by an absolute displacement of its mid-surface and a relative displacement of its top surface, such that difficulties of finite rotations are avoided. To maintain transverse isotropy in shells, viscoplastic effects of the transverse shear strains are Implicit time algorithm is used for time discretization of neglected. the rate effects. The final discretized equations are solved by a Newton-Raphson scheme. Due to the transversely isotropic nature of the shell element, the single point reduced Gauss quadrature is used to evaluate transverse shear effects in both the tangent stiffness matrix and the internal force vector. This shell element is therefore applicable to both thick and thin shells. Several numerical examples are solved to verify the validity of the assumptions and to demonstrate the accuracy and versatility of the proposed method. |
Year | 1981 |
Type | Dissertation |
School | School of Engineering and Technology |
Department | Department of Civil and Infrastucture Engineering (DCIE) |
Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
Chairperson(s) | Karasudhi, Pisidhi ; Worsak Kanok-Nukulchai |
Examination Committee(s) | Gupta, Ashim Das ; Loo, Yew-Chaye ; Panitan Lukkunaprasit |
Scholarship Donor(s) | The Japanese Government |
Degree | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering, School of Engineering and Technology |
Contributor(s) | Elastic plates and shells |