The energy parameter, defined for random loadings, is analysed. Under uniaxial loading this parameter distinguishes between the strain energy densities for tension (positive) and compression (negative). For the centered stochastic loading we obtain a random history of strain energy density with zero expected value. Under multiaxial loadings the normal strain energy density in the critical plane is understood as the energy parameter. For life time calculation the history of strain energy density is schematized with use of the rain-flow algorithm. Fatigue damage is accumulated according to Palmgren-Miner hypothesis. The proposed parameter was successfully verified during fatigue tests of cruciform specimens subjected to biaxial non-proportional random tension-compresion.
展开▼
