DESCRIPTION OF MULTIAXIAL CYCLIC STRESS-STRAIN RELATIONSHIP WITH A SIMPLE APPROACH

摘要

The thin walled tubular specimens were used as researching objects. The multiaxial cyclic stress-strain relation under both proportional and nonproportional loading was studied according to the characteristic of the stress and strain on the critical plane and the researching results of multiaxial critical plane principle. First, the multiaxial cyclic stress-strain relation model under proportional loading is derived based on the uniaxial cyclic stress-strain relation, and then according to the researching results of the critical plane approach for multiaxial fatigue, multiaxial cyclic stress-strain relation is given under nonproportional loading. The experiments of tension-torsion proportional and nonproportional cyclic loading were conducted to verify multiaxial cyclic stress-strain relation proposed in this paper. The prediction of the model agrees with the experimental results reasonably well.