Evolution of discrete phenomena of inelasticity in aluminum alloy under cyclic loading

Abstract

An approach has been developed that allows assessing inelastic phenomena in a material based on the param eter o f the phase shift angle distribution between the stress and strain, which is measured in local zones on the surface o f the investigated material. The distribution o f the phase shift angle variance in the service life range investigated allows tracing the kinetics o f the discrete phenomena o f inelasticity in the material studied. It is show n in [5,6] that the process o f plastic deform ation taking place at a m icrolevel under cyclic loading is characterized by regular stage-like nature. The results o f the investigations o f inelasticity variation w ithin the high-cycle fatigue region [7][8][9] show that traditional concepts o f the scattered dam age progressing in stages in m etals and alloys at a m acrolevel can be extended by taking into account the scale level o f the analysis o f inelastic processes o f m aterial deform ation w hich reveal stochastic peculiarities at the m icrostructural level. This approach is of current im portance considering the fact that the characteristics o f inelastic processes in the material that w ere obtained on the basis o f the integral assessm ent do not reflect the discrete character o f the m aterial dam ageability under cyclic deform ation [10].The aim o f this w ork is to investigate the kinetics o f the discrete phenom ena o f inelasticity in the alum inum alloy under cyclic deform ation in the high-cycle fatigue region.