Locking-free 6-noded triangular shell elements based on hierarchic optimisation

Conforming lower-order shell elements based on Reissner-Mindlin plate theory generally exhibit an over-stiff response under loading, typically manifested through various forms of locking. A recently developed hierarchic optimisation approach addresses locking by enriching the conforming strains with strain terms towards objective ‘smoother’ distribution afforded element, which has proven to be effective in relieving shear, membrane and distortion 9-noded quadrilateral elements. Nevertheless, some practical structural problems that involve complex geometry, triangular are required avoid a highly distorted mesh This paper presents family 6-noded approach. The proposed curved not only effectively alleviate inaccuracies arising from locking, but also embrace desirable characteristics spatial isotropy insensitivity element distortion. have been incorporated within co-rotational framework allow large displacement analysis thin moderately thick plates shells. Several numerical examples finally presented demonstrate effectiveness accuracy formulation as well its superior locking-free performance compared existing • Novel Mitigation via optimisation. Objective corrective assumed-strain variants including isotropy. Incorporation for analysis. Element variant H3O6 offers MITC6 element.