Isoparametric Quadratic Thick Curved Beam Element

摘要

A three-noded curved beam element with transverse shear deformation, based on independent isoparametric quadratic interpolations is designed from field-consistency principles. It is shown that a quadratic element that is field-inconsistent in membrane strain effects from membrane locking - i.e., an error of the second kind propagates indefinitely as element length to thickness ratio and/or element length to radius of curvature ratio increase, in nearly inextensional bending. However, field inconsistency in shear strain does not lead to shear locking but degrades its performance to exactly that of a field consistent linear element. It is also seen that field inconsistency leads to severe axial force and shear force oscillations. Error estimates for locking, wherever possible are derived and confirmed by numerical experiments.