Adaptive multi-point quadrature for elasticplastic shell elements
A multi-point integration scheme to enhance the coarse-mesh accuracy of the four-node quadrilateral shell element for elasticplastic simulations by explicit methods is described. Compared to 1-point quadrature elements, considerably improved results can be obtained by using this multi-point scheme in beam bending problems where a model with one or two layers of elements along the depth is employed. In the interest of efficiency, an adaptive scheme is devised in which the number of quadrature points depends on the state of the element. This speeds up the computation and maintains accuracy in the plastic range. The scheme is designed so that no incompatibility is introduced upon switching from 1-point to multi-point quadrature. The speed-up achieved by adaptive quadrature depends on problem parameters. Numerical examples show that this adaptive quadrature method effectively captures the in-plane bending behavior in elasticplastic simulations and achieves good efficiency.
elasticplastic finite elements non-linear structural mechanics