Calculation of low-cycle fatigue under nonproportional loading conditions

Procedure for the evaluation of the accumulation of defects in metallic structural materials under complex elastoplastic loading

“…The damageability of the material characterizes the dependence of the density of microdefects in a certain plane section of an element of the material on the action of external thermal and force factors. At present, there is no common point of view on the physical meaning of the parameter of damageability [7][8][9][10][11][12][13][14].Continual fracture mechanics (CFM) successfully develops for the last 40 years as a promising scientific trend in the mechanics of deformable bodies. The formation of this trend was initiated by Kachanov [4] and Rabotnov [5] who used the concept of internal variables [3, 9, 12] with a system of the corresponding kinetic equations and fracture criteria in the stage of initiation of a microcrack.…”

“…The damageability of the material characterizes the dependence of the density of microdefects in a certain plane section of an element of the material on the action of external thermal and force factors. At present, there is no common point of view on the physical meaning of the parameter of damageability [7][8][9][10][11][12][13][14].…”

Damage of structural materials under complex low-cycle loading

“…It is shown that, in the general case of complex loading for the complex stress state, it is reasonable to use the specific energy of additional stresses (with regard for the arc of plastic strains in a loading cycle) as a parameter of damage for two types of fracture (rupture and shear).Keywords: low-cycle fatigue, Bauschinger effect, phenomenological models of accumulation of defects, specific energy of additional stresses.The process of elastoplastic deformation of structural materials is accompanied by the initiation, growth, and accumulation of defects [1][2][3][4][5][6][7][8][9]. It is generally agreed that microdamage should be regarded as a collection of continuous complex and poorly studied processes of changes running in materials under thermomechanical loads on the submicro-, micro-, and macrolevels and leading to the degradation of the mechanical properties of materials accompanied by the decrease in the load-carrying ability of the entire structure [1][2][3][4][5][6][7][8][9][10][11][12].…”

“…The process of elastoplastic deformation of structural materials is accompanied by the initiation, growth, and accumulation of defects [1][2][3][4][5][6][7][8][9]. It is generally agreed that microdamage should be regarded as a collection of continuous complex and poorly studied processes of changes running in materials under thermomechanical loads on the submicro-, micro-, and macrolevels and leading to the degradation of the mechanical properties of materials accompanied by the decrease in the load-carrying ability of the entire structure [1][2][3][4][5][6][7][8][9][10][11][12].…”