A COUNTERINTUITIVE REGION OF RESPONSE FOR ELASTIC-PLASTIC RINGS LOADED WITH AXISYMMETRICAL PRESSURE PULSES

We modeled the elastic-plastic response of 6061-T6 aluminium rings loa ded with internal, axisymmetric, short-duration pressure pulses. Our a nalysis used stress-strain data for specimens pulled beyond tensile yi eld, unloaded, and then compressed beyond compressive yield. These rev erse loading data showed the classical Bauschinger effect, where compr essive yield was significantly lower than tensile yield. We presented elastic-plastic response predictions for a 6 mus duration, sine-square d pressure pulse that closely approximates that in previously publishe d data. For a range of pressure pulse amplitudes beyond that required to cause yielding, our axisymmetric response model predicted final rad ial displacements that were radially inward or opposite in direction t o the pressure pulses. For larger pulse amplitudes, final radial displ acements were radially outward or in the direction of the pressure pul ses.