An approach to the determination of cyclic creep strain

1979 ◽  
Vol 11 (11) ◽  
pp. 1225-1229 ◽  
Author(s):  
V. P. Golub
Keyword(s):  
Creep Strain ◽  
Cyclic Creep

A Method for Estimating Creep Deformation of Structures Subjected to Cyclic Loading

1973 ◽  
Vol 40 (4) ◽  
pp. 928-934 ◽  
Author(s):  
J. J. Williams ◽  
F. A. Leckie
Keyword(s):  
Cyclic Loading ◽  
Creep Strain ◽  
Effective Stress ◽  
Creep Test ◽  
Creep Deformation ◽  
Cyclic Creep ◽  
Uniaxial Stress ◽  
Time Varying ◽  
Proportional Loading

A method is proposed for estimating structural creep deformation due to histories of cyclic proportional loading. The method applies to structures composed of materials whose creep strain due to constant uniaxial stress is given by an equation of the form ε(t)/ε0={σ/σ0}n{t/t0}m Knowledge of the form of the creep law for time-varying stress is not required, as use is made of an effective stress obtained from a single cyclic creep test.

scholarly journals Determining the rheological properties of viscoelastic materials by the values of creep strain

2019 ◽  
Vol 18 (3) ◽  
pp. 166-172
Author(s):  
E. Yu. Ivanov ◽  
V. A. Kirpichev
Keyword(s):  
Rheological Properties ◽  
Creep Strain ◽  
Viscoelastic Properties ◽  
Test Bench ◽  
Nonlinear Dependence ◽  
Rheological Characteristics ◽  
Viscoelastic Materials ◽  
Creep Curves ◽  
The Moment

Determination of creep strain arising due to stresses acting up to the moment of time t is considered. The phenomenon of constant-stress creep is described. A method is proposed to determine the parameters of the Arutyunyan creep kernel selected to describe the behavior of a material using two creep curves of a material with viscoelastic properties and nonlinear dependence of creep strain on the stress. In addition, the constant in the expression describing nonlinear dependence of creep strain on the stress is defined. The AMg6M alloy, widely used in the design of aerospace products, was chosen as the material to be analyzed. The tests were carried out on samples 3 mm thick at strains of 65 MPa and 156.9 MPa. According to the results of testing samples of materials on the test bench of Samara University creep curves were obtained. By determining the parameters of the approximation of the Arutyunyan kernel and the parameter included in the expression of nonlinear dependence of creep strain on the stress, it is possible to determine the value of the creep strain of the material for arbitrary values of stress and time. Comparison of the experimental and calculated creep curves for the AMg6M alloy confirms the validity of determination of the rheological characteristics of the tested material.

Determination of the life of constructional steels under conditions of cyclic creep in the plane stressed state

1983 ◽  
Vol 15 (10) ◽  
pp. 1356-1358 ◽  
Author(s):  
F. F. Giginyak ◽  
M. V. Storchak
Keyword(s):  
Stressed State ◽  
Cyclic Creep ◽  
Plane Stressed State

scholarly journals Effect of Cyclic Loading on the Creep Performance of Silicon Nitride

1996 ◽  
Vol 118 (2) ◽  
pp. 251-256 ◽  
Author(s):  
A. A. Wereszczak ◽  
M. K. Ferber ◽  
T. P. Kirkland ◽  
C.-K. J. Lin
Keyword(s):  
Silicon Nitride ◽  
Plastic Strain ◽  
Creep Strain ◽  
Strain Relaxation ◽  
Cyclic Creep ◽  
Cyclic Fatigue ◽  
Fatigue Tests ◽  
Dominant Component ◽  
Static Creep ◽  
Stressing Rate

Tension–tension cyclic fatigue tests (triangular waveform, σmax = 100 MPa, R = 0.1) were conducted on hot isostatically pressed (HIPed) silicon nitride at frequencies spanning several orders of magnitude (5.6 × 10−6 to 0.1 Hz or 10−3 MPa/s to 18 MPa/s) at 1370°C in air. The amount of cyclic creep strain was found to be a function of the frequency or stressing rate, with greater strains to failure observed as the frequency or stressing rate decreased. The total strain was viewed as the sum of elastic, anelastic (or transient recoverable), and plastic (viscous or nonrecoverable) strain contributions, after the empirical Pao and Marin model. The plastic strain was found to be the dominant component of the total creep and was unsatisfactorily represented by the Pao and Marin model. To circumvent this, a time exponent was introduced in the plastic strain term in the Pao and Marin model. This modification resulted in good correlation between model and experiment at the slower frequencies examined but overpredicted the cyclic creep strain at the faster frequencies. The utility of using the modified Pao and Marin model to predict cyclic creep response from static creep and strain relaxation tests is described.

Effect of stress levels on compressive low-cycle fatigue behaviour of softwood

Holzforschung ◽  
2005 ◽  
Vol 59 (6) ◽  
pp. 662-668 ◽  
Author(s):  
Meng Gong ◽  
Ian Smith
Keyword(s):  
Mathematical Model ◽  
Creep Strain ◽  
Stress Level ◽  
Low Cycle Fatigue ◽  
Total Duration ◽  
Peak Stress ◽  
Cyclic Creep ◽  
Cycle Fatigue ◽  
Creep Tests ◽  
Stress Levels

Abstract Low-cycle fatigue (LCF) of spruce under parallel-to-grain compression was investigated to simulate the damage that occurs during extreme events such as hurricanes. Load control was used, with peak stress levels of 75%, 85% and 95% of static compressive strength (C max). Changes in the residual cyclic modulus, cyclic creep strain and modified work density were correlated with the number of load cycles to assess their suitability as damage indicators. Creep tests were also carried out and the strain compared with cyclic creep strain under LCF load. Fatigue and creep tests had a total duration of 10 min. A three-element mathematical model was used to predict the cyclic creep strain. Some key findings were that: (1) the residual cyclic modulus varies with the number of load cycles at a given stress level and decreases with an increase in stress level; (2) cyclic creep strain and pure creep strain are strongly influenced by the peak stress level; and creep specimens fail but fatigue specimens do not at a 95% peak stress level; and (3) the three-element mathematical model is appropriate for predicting cyclic creep strain.

Determination of creep properties of an advanced Fe-Cr-Ni alloy using small punch creep test with a modified creep strain model

2019 ◽  
Vol 104 ◽  
pp. 102324 ◽  
Author(s):  
Lei Zhao ◽  
Kai Song ◽  
Lianyong Xu ◽  
Yongdian Han ◽  
Hongyang Jing ◽  
...  
Keyword(s):  
Creep Strain ◽  
Creep Test ◽  
Creep Properties ◽  
Small Punch ◽  
Ni Alloy ◽  
Strain Model ◽  
Small Punch Creep Test

A Method for Quantifying Creep Strain Due to Cyclic Stress

1974 ◽  
Vol 41 (4) ◽  
pp. 953-958 ◽  
Author(s):  
J. J. Williams ◽  
F. A. Leckie
Keyword(s):  
Creep Strain ◽  
Creep Test ◽  
Cyclic Creep ◽  
Cyclic Stress ◽  
Constant Stress ◽  
Stress Tests ◽  
Creep Strains

A method is proposed for isolating the two constants required to quantify the creep strains caused by cyclic histories of stress. These constants can be determined from the results of a single cyclic creep test together with data from constant stress tests.

Determination of cyclic creep in mild steel using an overstress plasticity model

1986 ◽  
Vol 80 (2) ◽  
pp. 195-202 ◽  
Author(s):  
H.D. Chandler
Keyword(s):  
Mild Steel ◽  
Cyclic Creep ◽  
Plasticity Model

scholarly journals Effect of Cyclic Loading on the Creep Performance of Silicon Nitride

1995 ◽  
Author(s):  
Andrew A. Wereszczak ◽  
Mattison K. Ferber ◽  
Timothy P. Kirkland ◽  
Chih-Kuang J. Lin
Keyword(s):  
Silicon Nitride ◽  
Plastic Strain ◽  
Creep Strain ◽  
Strain Relaxation ◽  
Cyclic Creep ◽  
Cyclic Fatigue ◽  
Fatigue Tests ◽  
Recoverable Strain ◽  
Dominant Component ◽  
Stressing Rate

Tension-tension cyclic fatigue tests (triangular waveform, σmax = 100 MPa, R = 0.1) were conducted on hot isostatically pressed (HIPed) silicon nitride at frequencies spanning several orders of magnitude (5.6×10−6 to 0.1 Hz or 10−3 MPa/s to 18 MPa/s) at 1370°C in air. The amount of cyclic creep strain was found to be a function of the frequency or stressing rate with greater strains to failure observed as the frequency or stressing rate decreased. The total strain was viewed as the sum of elastic, anelastic (or transient recoverable), and plastic (viscous or non-recoverable) strain contributions, after the empirical Pao and Marin model. The plastic strain was found to be the dominant component of the total creep and was unsatisfactorily represented by the Pao and Marin model. To circumvent this, a time exponent was introduced in the plastic strain term in the Pao and Marin model. This modification resulted in good correlation between model and experiment at the slower frequencies examined but over-predicted the cyclic creep strain at the faster frequencies. The utility of using the modified Pao and Marin model to predict cyclic creep response from static creep and strain relaxation tests is described.

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