1 AIT Asian Institute of Technology

A large deformation analysis of elastoviscoplastic shells by finite element method

AuthorRao, Vakkalagadda Venkata Sreedhara
Call NumberAIT Diss. no. ST-81-01
NoteA dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering, School of Engineering and Technology
PublisherAsian Institute of Technology
AbstractA 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.
Year1981
TypeDissertation
SchoolSchool of Engineering and Technology
DepartmentDepartment of Civil and Infrastucture Engineering (DCIE)
Academic Program/FoSStructural 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
DegreeA 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


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