Three dimensional hybrid-Trefftz stress finite elements for plates and shells

Abstract

Copyright © 2017 John Wiley & Sons, Ltd.Three-dimensional hybrid-Trefftz stress finite elements for plates and shells are proposed. Two independent fields are approximated: stresses within the element and displacement on their boundary. The required stress field derived from the Papkovitch-Neuber solution of the Navier equation, which a priori satisfies the Trefftz constraint, is generated using homogeneous harmonic polynomials. Restriction on the polynomial degree in the coordinate measured along the thickness direction is imposed to reduce the number of independent terms. Explicit expressions of the corresponding independent polynomials are listed up to the fifth order. Illustrative applications to evaluate displacements and stresses are conducted by hexahedral hybrid-Trefftz stress element models. The hierarchical p- and h-refinement strategy are exploited in the numerical tests.

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