The alteration of substructure of an austenitic stainless steel has been investigated during con- stant strain fatigue.No plateau stage on the cyclic stress-strain curve was observed for the stainless steel in contras...The alteration of substructure of an austenitic stainless steel has been investigated during con- stant strain fatigue.No plateau stage on the cyclic stress-strain curve was observed for the stainless steel in contrast with a monocrystalline pure copper specimen.This may relate to its low stacking fault energy.During strain fatigue under various amplitudes the substructure of dislocation in austenite alterates correspondingly.It revealed to associate with the appearance change of the cyclic stress-strain curve.展开更多
The cyclic stress-strain responses (CSSR), Neuber's rule (NR) and cyclic strain-life relation (CSLR) are treated as probabilistic curves in local stress and strain method of low cycle fatigue analysis. The randomn...The cyclic stress-strain responses (CSSR), Neuber's rule (NR) and cyclic strain-life relation (CSLR) are treated as probabilistic curves in local stress and strain method of low cycle fatigue analysis. The randomness of loading and the theory of fatigue damage accumulation (TOFDA) are considered. The probabilistic analysis of local stress, local strain and fatigue life are constructed based on the first-order Taylor's series expansions. Through this method proposed fatigue reliability analysis can be accomplished.展开更多
An experimental investigation on the mechanical mechanisms of fatigue micro-crack initiation and propagation of a nickel-based superalloy is presented. By coupling digital image correlation method and scanning electro...An experimental investigation on the mechanical mechanisms of fatigue micro-crack initiation and propagation of a nickel-based superalloy is presented. By coupling digital image correlation method and scanning electron microscope, the fatigue residual strain distribution at the grain scale has been obtained. The results showed that there is a trend of accumulation for the residual strain. Micro-cracks are more likely to initiate in or near the areas with particularly large residual strain, and propagate along the large-strain paths.展开更多
文摘The alteration of substructure of an austenitic stainless steel has been investigated during con- stant strain fatigue.No plateau stage on the cyclic stress-strain curve was observed for the stainless steel in contrast with a monocrystalline pure copper specimen.This may relate to its low stacking fault energy.During strain fatigue under various amplitudes the substructure of dislocation in austenite alterates correspondingly.It revealed to associate with the appearance change of the cyclic stress-strain curve.
文摘The cyclic stress-strain responses (CSSR), Neuber's rule (NR) and cyclic strain-life relation (CSLR) are treated as probabilistic curves in local stress and strain method of low cycle fatigue analysis. The randomness of loading and the theory of fatigue damage accumulation (TOFDA) are considered. The probabilistic analysis of local stress, local strain and fatigue life are constructed based on the first-order Taylor's series expansions. Through this method proposed fatigue reliability analysis can be accomplished.
基金supported by the National Natural Science Foundation of China (NSFC, Nos. 11002048, 10972072)the National Basic Research Program of China (973 Program, No. 2007CB714104)the Special Fund of State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering at Hohai University (No. 2009585912)
文摘An experimental investigation on the mechanical mechanisms of fatigue micro-crack initiation and propagation of a nickel-based superalloy is presented. By coupling digital image correlation method and scanning electron microscope, the fatigue residual strain distribution at the grain scale has been obtained. The results showed that there is a trend of accumulation for the residual strain. Micro-cracks are more likely to initiate in or near the areas with particularly large residual strain, and propagate along the large-strain paths.
