An unsymmetric 8-node hexahedral solid-shell element based on ANS and incompatible concepts for thin shell analysis

In this paper, an incompatible unsymmetric 8-node hexahedral solid-shell element is proposed with different sets of trial and test functions. The trial functions used in the 8-node hexahedral solid element in our previous work are adopted with minor revision. In addition, to eliminate the transverse shear and trapezoidal locking in the calculation of thin shell structures, the test functions are revised by the assumed natural strain method. The present solid-shell element inherits advantages from the original solid element and also alleviates the typical locking phenomena for shell elements. Numerical investigations show that the present element is insensitive to mesh distortion and has rapid convergence. In the tests of thin shell structures with bending, it can also provide locking-free predictions with high precision. Finally, the present element is extended to geometrically nonlinear analysis and its accuracy is demonstrated by a simple numerical example. (c) 2023 Elsevier B.V. All rights reserved.