Ratchetting: Recent progresses in phenomenon observation, constitutive modeling and application

Influence of non-proportional loading on ratcheting responses and simulations by two recent cyclic plasticity models

Time-dependent ratchetting experiments of SS304 stainless steel

Uniaxial ratcheting and fatigue failure of tempered 42CrMo steel : Damage evolution and damage-coupled visco-plastic constitutive model

The ratchetting behaviour and fatigue failure, as well as their interaction were investigated by uniaxial cyclic stressing tests for SS304 stainless steel at room temperature. The ratchetting strain and fatigue life of the material were measured in different loading levels. The effects of mean stress, stress amplitude and stress ratio on the ratchetting strain and final failure life were discussed. Simultaneously, the variations of responded strain amplitude with the number of cycles were illustrated to discuss the interaction of ratchetting behaviour and fatigue failure. The experimental results show that the ratchetting strain and fatigue life of the material depend greatly on mean stress, stress amplitude and stress ratio of uniaxial cyclic stressing, and two kinds of failure modes (i.e., ratchetting failure with obvious necking due to large ratchetting strain and fatigue failure due to low-cycle fatigue with nearly constant responded strain amplitude) take place respectively, depending on the stress level prescribed in the tests.

Experimental study on ratchetting-fatigue interaction of SS304 stainless steel in uniaxial cyclic stressing

Uniaxial ratcheting and failure behaviors of two steels

Non-proportionally multiaxial ratcheting of cyclic hardening materials at elevated temperatures: Experiments and simulations

The cyclic deformation of three structural steels, SS316L stainless steel, 40Cr3MoV bainitic steel and 2 5CDV4.11 steel, were studied experimentally by uniaxial cyclic straining or stressing tests at room temperature. The cyclic softening/hardening behaviours of the steels were discussed first by cyclic straining tests; and then the effects of cyclic softening/hardening behaviours on the uniaxial ratchetting of the materials were investigated by asymmetrical cyclic stressing tests. It is concluded from the experimental results that the ratchetting greatly depends on the cyclic softening/hardening behaviours of the materials, as well as the loading history. Different ratchetting and failure behaviours are observed for the prescribed steels. It is also stated that the proposed unified visco-plastic constitutive model can provide a fairly reasonable simulation of the uniaxial ratchetting of SS316L stainless steel and 25CDV4.11 steel; but cannot simulate the ratchetting of 40Cr3MoV bainitic steel since the dependence of cyclic softening behaviours on the applied inelastic strain amplitude cannot be reasonably described in the discussed constitutive model. Some significant conclusions are obtained, which are useful to construct constitutive model to describe the ratchetting of the materials with different cyclic softening/hardening behaviours.

Youguo Li

Papers

Uniaxial ratcheting and failure behaviors of two steels

Non-proportionally multiaxial ratcheting of cyclic hardening materials at elevated temperatures: Experiments and simulations

Uniaxial ratchetting in steels with different cyclic softening/hardening behaviours

Vertical short-crack behavior and its application in rolling contact fatigue