Flexure and torsion locking phenomena in out-of-plane deformation of Timoshenko curved beam element

► We identify flexure and torsion locking phenomena in Timoshenko curved beam element. ► We characterize these phenomena based on flexure-to-torsion (EI/GJ) stiffness ratio. ► Flexure locking is dominant in the regime EI/GJ>1, and torsion locking in EI/GJ<1. ► These phenomena are due to inconsistency in out-of-plane strain field interpolations. ► Consistent field interpolations eliminate these locking in all regimes of EI/GJ.