A C° Elastoplastic Shell Element Based on Assumed Covariant Strain Interpolations
A curved 9-node C° shell finite element for elastoplastic analysis is proposed which is free from serious locking problems, does not possess hourglass modes and provides solutions which are quite insensitive to mesh distortion. The element is based on the use of modified strain fields which are obtained from assumed interpolations of covariant (non-physical) strains referred to the element natural coordinate system. The linear elastic shell formulation is described first and this is then extended for an elastoplastic constitutive model. A return mapping algorithm is introduced for integration of the rate constitutive equations under the zero normal stress hypothesis. Some numerical results, illustrating the good convergence characteristics of the element, are reported.
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- H.C.Huang and E.Hinton, “An Improved Lagrangian 9-node Mindlin Plate Element,” Proc. Numeta ′85 Conference/Swansea Jan 1985.Google Scholar
- J.Jang and P.M.Pinsky, “A Covariant Strain Based 9-Node Shell Element,” To appear, Int. J. Num. Meth. Engr.Google Scholar
- J.H.Jang and P.M.Pinsky, “Converg ence of Curved Shell Elements Based on Assumed Covariant Strains,” To appear, Int. J. Num. Meth. Engr.Google Scholar
- J.Jang, “Curved Shell Finite Elements Based on Assumed Covariant Strain Interpolations,” Ph.D. Thesis, Stanford University, Stanford, California (1987).Google Scholar
- P.M. Pinsky and J. Jang, “An Elastoplastic Curved Shell Finite Element Based on Assumed Covariant Strain Interpolations,” Submitted to Engineering Mechanics, ASCE.Google Scholar
- P.M. Pinsky and J. Jang, “Convergence of Transverse Shear Stress in Plate Elements Based on Assumed Covariant Strain Interpolations,” Submitted to Computers and Structures.Google Scholar
- L.S.D. Morley and A.J.Morris, “Conflict Betwe en Finite Elements and Shell Theory,” Royal Aircraft Establishment Report, London (1978).Google Scholar