On the basis of the new methods for straight and curved beam analysis proposed in previous study, a Numerical Manifold Method for curved shell analysis based on independent covers is presented. In the mode of solid analysis, the Reissner-Mindlin assumption for 3D plate and curved shells is strictly simulated just by eliminating some terms of polynomial cover functions. And therefore the complexity of the derivation for the governing equation of curved shells and the corresponding numerical calculation formula is avoided. By means of the local coordinate system varying with the middle layer of the shell described by parametric equations, and also by calculating the derivatives of the local coordinates and the direction cosines with respect to the global coordinates, curved shell analysis based on exact geometric description can be realized. The detailed procedures including the integrating method and geometric formula are given. Examples of a spherical shell and a plate are used to verify the convergence of the method. In the end, the characteristics and advantages of the new method for beam, plate and shell analysis are summarized, including the complete solution for locking problem, via previous studies of 2D straight and curved beams as well as the study of 3D plates and curved shells in this paper.
Key words
curved shell /
exact geometry /
Numerical Manifold Method (NMM) /
independent covers /
beam, plate and shell analysis
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References
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