Influence of axial pre-load on plastic failure of beams subjected to transverse dynamic load

By employing a rigid-plastic approach together with interactive yield criteria, three fundamental failure modes of pre-tensioned clamped beams subjected to transverse impulsive loading are examined to identify the influence of axial pre-load. It is demonstrated that pre-tension will reduce the maximum transverse deflection at the midpoint (Mode I); increase the threshold impulsive velocity for onset of tensile tearing at the supports (Mode II); but make the beam more easily to fail in transverse shear failure at the supports (Mode III). When pre-tension reaches a certain value, Mode III occurs at a lower impulsive velocity than Mode II. The Pre-tension is found to have a larger influence on Mode III failure than on Modes I and II failures.