scholarly journals Anomalies in the elastic properties of metals at very high cycle loading and kinetics of damage accumulation

2017 ◽  
pp. 63-70
Author(s):  
M.V. Bannikov ◽  
◽  
I.A. Bannikova ◽  
S.V. Uvarov ◽  
O.B. Naimark ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Damage Accumulation ◽  
Cycle Loading ◽  
Kinetics Of ◽  
Very High

scholarly journals Kinetics of deformation and damage accumulation in concentration zones with nonisothermal low-cycle loading

1985 ◽  
Vol 17 (8) ◽  
pp. 1050-1056
Author(s):  
A. G. Kazantsev ◽  
A. P. Gusenkov ◽  
A. N. Chernykh
Keyword(s):  
Damage Accumulation ◽  
Cycle Loading ◽  
Kinetics Of

scholarly journals Evaluation of fatigue life of polycrystalline structural alloys

2018 ◽  
Vol 226 ◽  
pp. 03021
Author(s):  
Ivan A. Volkov ◽  
Leonid A. Igumnov ◽  
Aleksandr A. Ipatov
Keyword(s):  
Plastic Deformation ◽  
Damage Accumulation ◽  
Failure Process ◽  
Block Type ◽  
Elastoplastic Behavior ◽  
Evolutionary Equations ◽  
Defining Relations ◽  
Cycle Loading ◽  
Main Effects ◽  
Kinetics Of

A mathematical model describing the processes of elastoplastic deformation and damage accumulation under low-cycle loading has been developed, based on the viewpoint of mechanics of damaged media (MDM). The MDM model consists of three interrelated parts: defining relations describing elastoplastic behavior of the materials, taking into account its dependence on the failure process; evolutionary equations describing the kinetics of damage accumulation; strength criteria of the damaged material. In order to assess the reliability and scope of applicability of the defining relations of mechanics of damaged media, the processes of plastic deformation and damage accumulation in variety of structural steels in low-cycle tests have been numerically analyzed, and numerical results obtained have been compared with the data of full-scale experiments. It is shown that the presented model of mechanics of damaged media adequately describes, both qualitatively and quantitatively, with accuracy, necessary for practical calculations, the main effects of the processes of plastic deformation and damage accumulation in structural alloys under block-type non-stationary non-symmetrical low-cycle loading.

Study of the regularities of resistance to deformation and damage accumulation under irregular low cycle loading

2021 ◽  
Vol 87 (11) ◽  
pp. 55-63
Author(s):  
M. M. Gadenin
Keyword(s):  
Elastoplastic Deformation ◽  
Damage Accumulation ◽  
Low Cycle Fatigue ◽  
Functional Dependence ◽  
Experimental Studies ◽  
Similar Data ◽  
Cycle Loading ◽  
Cyclic Elastoplastic Deformation ◽  
Loading Modes ◽  
Kinetics Of

The results of computation and experimental studies of changes in the regularities of the strain resistance and damage accumulation in conditions of the irregular low cycle loading are presented and compared with similar data for a regular cyclic elastoplastic deformation at the same loading. The irregular mode of low cycle loading implemented in the study is adopted in the form of an equiprobable distribution of changes in the stress amplitudes within a given range between maximum and minimum levels at the symmetric form of the cycles. This mode was reproduced on test equipment through introduction of the corresponding functional dependence of changes in the stress amplitude in the cycles into the control program. The data on a cycle-by-cycle kinetics of both cyclic and unilaterally accumulated strains obtained under irregular mode of loading were recorded in a databank and then compared with the data for a regular loading. This provided the possibility of their analytical description by the corresponding equations of state with the correction of the parameters of the diagrams of cyclic elastoplastic deformation taking into account the conditions of irregularity of loading modes. The results of the experiments are presented in the form of diagrams of the tests modes, curves of a low cycle fatigue of the studied material at the soft and hard loading modes, diagrams of a cycle-by-cycle kinetics of the cyclic and accumulated strains at the regular and irregular modes, and also as kinetic diagrams of damages accumulation for these conditions. Using the summation criteria expressed through the deformation characteristics of accumulated damage, it is shown that taking into account change in the character of the strain development under irregular low-cycle loading, the criterion dependences can be used to assess the durability and compare it with the similar data under regular modes when accepting the condition of attaining the limiting state.

The effect of heterotrophic yield on the assessment of the correction factor for anoxic growth

1996 ◽  
Vol 34 (5-6) ◽  
pp. 67-74 ◽  
Author(s):  
D. Orhon ◽  
S. Sözen ◽  
N. Artan
Keyword(s):  
Correction Factor ◽  
Domestic Sewage ◽  
Yield Coefficient ◽  
Heterotrophic Growth ◽  
Metabolic Processes ◽  
Anoxic Conditions ◽  
Industrial Wastewaters ◽  
Systems Modelling ◽  
Kinetics Of ◽  
Very High

For single-sludge denitrification systems, modelling of anoxic reactors currently uses the kinetics of aerobic heterotrophic growth together with a correction factor for anoxic conditions. This coefficient is computed on the basis of respirometric measurements with the assumption that the heterotrophic yield remains the same under aerobic and anoxic coditions. The paper provides the conceptual proof that the yield coefficient is significantly lower for the anoxic growth on the basis of the energetics of the related metabolic processes. This is used for the interpretation of the very high values for the correction factor experimentally determined for a number of industrial wastewaters. A default value for the anoxic heterotrophic yield coefficient is calculated for domestic sewage and compatible wastewaters and proposed for similar evaluations.

Kinetics of a crack with varied rigidity under conditions of low-cycle loading

1976 ◽  
Vol 8 (10) ◽  
pp. 1217-1221
Author(s):  
V. Ya. Yablonko ◽  
V. I. Erofeev
Keyword(s):  
Cycle Loading ◽  
Kinetics Of

Elastic Properties of Steps at Interphase Boundaries

1991 ◽  
Vol 238 ◽  
Author(s):  
G. J. Shiflet
Keyword(s):  
Energy Density ◽  
Elastic Properties ◽  
Mathematical Analysis ◽  
Strain Energy ◽  
Chemical Processes ◽  
Diffusion Kinetics ◽  
Interphase Boundaries ◽  
Kinetics Of ◽  
Maximum Stresses

ABSTRACTStresses are introduced in crystals at interphase boundaries where steps improve the registry of atoms. A model and mathematical analysis based on an approach previously taken by van der Merwe and Shiflet1–4 of the problem incorporating a coherent step are presented. Computed distributions of stresses, strains, dilatation and energy density in the form of contours and nets are given for a coherent monatomic step. It is concluded that the maximum stresses are quite large and the fields decay fairly rapidly with distance from the steps, the gradient of dilatation around steps will significantly affect diffusion kinetics of impurities and the strain energy seems too low to significantly enhance chemical processes.

Sign in / Sign up

Export Citation Format

Share Document