Locking-free robust finite element approximation of thin shell-like structures

In the structural analysis of thin elastic structures using standard FEMs within the poor approximation space, the numerical results may suffer from the quality deterioration called the locking phenomenon. This situation becomes more crucial for the structures with non-vanishing curvatures, such as arch- and shell-like bodies, owing to the additional membrane constraints. In addition, the choice of unsuitable shear correction factor (SCF), in dimen-sionally-reduced first-order analysis models, may become an additional source for the quality deterioration. In this context, we here propose a locking-free robust finite element approximation for the robust structural analysis of shell-like structures, by improving the degenerated 8-node shell element. In order to completely overcome the quality deterioration according to the thickness reduction, we combine the reduced integration (RI) and the modified shear correction factor.