Investigations of creep ratcheting on thick-walled tubes

Mean stress and ratcheting corrections in fatigue life prediction of metals

“…The left side of Eqn ( 23) can be interpreted as the mean stress corrected ductility of a material, where the success of the mean stress corrections to the material ductility can be characterised by the degree to which the resulting data points consolidate with the line of Eqn (23). The plots of this diagram of seven types of materials are shown in Fig.…”

“…Recently, the ratcheting fatigue of specific engineering materials was extensively studied in [15][16][17][18][19][20][21][22][23][24][25][26] , which is generally modelled by cyclic plasticity hardening rules. Wang et al 15 studied the effects of the pre-strain and mean stress on the cyclic deformation and fatigueratcheting behaviour of Z2CN18.10 steel.…”

“…Through capturing the distinctive strain ratcheting behaviour near the crack tip, Tong et al 29 explored the ratcheting strain as a crack-driving force in controlling time-independent and time-dependent crack growth, using elasto-plastic, visco-plastic and crystal-plasticity constitutive models; they indicated that both ratcheting strain and accumulated plastic strain might be used to model the crack growth. According to the experimental observations in [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] , the ratcheting behaviour differs for various materials, and the ratcheting-fatigue interaction involves the effects of the loading waveform parameters, cyclic softening/hardening behaviour, and micro-structural characteristics of the materials.…”

Mean Stress and Ratcheting Corrections in Fatigue Life Prediction of Metals

“…For the design and assessment of engineering components, the ratcheting-fatigue interaction should be modeled and predicted accurately under cyclic loadings. The ratcheting phenomenon has been modeled by cyclic plasticity hardening rules in the last two decades [5][6][7][8][9][10][11][12][13][14][15].…”