Notice of RetractionShear response of a clamped beam subjected to intense dynamic loading with considering weakening effect of the shear sliding cross-section
The present paper, adopting a rigid, perfectly plastic idealization material model and a square yield locus, with the consideration of two conditions of weakening and non-weakening effects of transverse shear sliding section, analyses the shear response of a clamped beam in the initial plastic deformation stage subject to a uniformly distributed impulsive loading and the precondition of possible shear failure mode, writes the shear's movement equation, puts forward the expressions of shear velocity and shear sliding volume, finally the conclusion of the availability of different shear response model for weakening effect is drawn.
Broken beams
A series of experiments has been conducted, utilizing sheet explosive opplied to clamped aluminum beams, with a neoprene buffer. As the load is monotonically increased, three damage modes are identified, which respecitively are major inelastic deformation, tearing at the extreme fiber, and transverse shear at the support.Satisfactory correlation is reported for the extent of inelastic deformation using a lumped parameter, finite-difference code; thresholds for tearing and shear failure based on empirical criteria are presented. Using a Timoshenko beam theory, the shear threshold appears to be dependent on the section velocity, rather than upon the shear stress.
An analysis of the shear failure of rigid-linear hardening beams under impulsive loading
A theoretical rigid-plastic analysis for the dynamic shear failure of beams under impulsive loading is presented when using a travelling plastic shear hinge model which takes into account material strain hardening. The maximum dynamic shear strain and shear strain-rate can be predicted in addition to the permanent transverse deflections and other parameters. The conditions for the three modes of shear failure, i.e., excess deflection failure, excess shear strain failure and adiabatic shear failure are analyzed. The special case of an infinitesimally small plastic zone is discussed and compared with Nonaka's solution for a rigid, perfectly plastic material. The results can also be generalized to examine the dynamic response of fibre-reinforced beams.