Cyclic Plasticity and Low Cycle Fatigue Life in Variable Amplitude Loading

Polák, Jaroslav; Klesnil, M.

doi:10.1111/j.1460-2695.1979.tb00371.x

Cited by 57 publications

(70 citation statements)

References 9 publications

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“…Fig. 4a shows the tensile and compression hysteresis half-loops plotted in relative stress σ r vs. fictive stress ε r E eff /2 [2]. The half of the relative strain ε r multiplied by compression or tension effective modulus (see Table 3) are used for the calculation of the fictive stress.…”

Section: Resultsmentioning

confidence: 99%

“…The half of the relative strain ε r multiplied by compression or tension effective modulus (see Table 3) are used for the calculation of the fictive stress. The shape of the halfloops was analyzed by plotting the first and the second derivatives of tensile or compression halfloops (divided by effective modulus E eff and by the half of the square of effective modulus) vs. fictive stress (Figs 4b and 4c) [2,4]. Both effective moduli E eff are found from the first derivative at relative strain where the second derivative reaches its first minimum.…”

Section: Resultsmentioning

confidence: 99%

“…The tests were conducted at temperature 800 °C in air. Multiple step test method [2] was used for obtaining cyclic stress-strain curve, therefore only one specimen was needed to obtain cyclic stress-strain curve. Data recording rate was under 0.3 ms in order to record high number of data on the hysteresis loop.…”

Section: Methodsmentioning

confidence: 99%

“…Data recording rate was under 0.3 ms in order to record high number of data on the hysteresis loop. Using maximum and minimum strains in cycles, the relative strain ε r and the relative stress σ r [2] were calculated for the tensile and for the compressive hysteresis half-loops. The first and the second derivatives of the hysteresis half-loops were obtained using smoothing numerical procedures.…”

Section: Methodsmentioning

confidence: 99%

“…Analysis of hysteresis loops shape can provide important information about the sources of the high cyclic stress in such complex materials. The aim of this paper was to conduct cyclic test at 800°C of two commonly used cast polycrystalline superalloys (IN 738LC and IN 792-5A) and study cyclic stress-strain response of these materials using generalized statistical theory of the hysteresis loop [2].…”

Section: Introductionmentioning

confidence: 99%

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Analysis of the Effective and Internal Cyclic Stress Components in the Inconel Superalloy Fatigued at Elevated Temperature

Šmíd

Petrenec

Polák

et al. 2011

AMR

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Abstract. Cyclic multiple step test in strain control have been performed on cylindrical specimens of cast polycrystalline Inconel 738LC and 792-5A superalloys at 800 °C in laboratory atmosphere. Hysteresis loops were analyzed according to the statistical theory of hysteresis loop. The effective and internal stress components were evaluated. The effective stress of γ´ precipitate has significant influence on the stress-strain response both materials. The stress amplitude in IN 792-5A is higher than in IN 738LC at approximately same total strain amplitude due to significantly higher effective stress of γ´ phase. Cyclic hardening/softening curves and cyclic stress-strain curves using short-cut procedure were obtained. Cyclic hardening/softening behavior depends both on temperature and strain amplitude. Low amplitude straining is characterized by the saturation of the stress amplitude. In high amplitude straining slight softening was found. The cyclic stress-strain curves for both materials can be fitted by power law. Cyclic stress-strain response in terms of internal and effective stress components is discussed in relation to microstructural parameters of the materials. The observation of surface relief revealed the presence of persistent slip markings.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Analysis of the Effective and Internal Cyclic Stress Components in the Inconel Superalloy Fatigued at Elevated Temperature

Šmíd

Petrenec

Polák

et al. 2011

AMR

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Mechanical Properties of BNM at Ambient Temperature

Valiev¹,

Zhilyaev²,

Langdon³

2013

Bulk Nanostructured Materials

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Quantifying Rock Fatigue and Decreasing Compressive and Tensile Strength after Repeated Freeze‐Thaw Cycles

Jia

Xiang

Krautblatter

2015

Permafrost & Periglacial

103

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Frost action is believed to control rock slope erosion in cold environments and is a major driver of rockfall generation. While other frost weathering by ice segregation has been proved effective in previous laboratory studies, we investigate the effects of volumetric expansion on samples of sandstone because it is the best-constrained process for quantifying damage. We conducted up to 17 freeze-thaw cycles using 26 identical sandstone cylinders and repeatedly measured porosity, elastic moduli and compressive and tensile strength in the laboratory. To analyse the damage mechanism, we monitored strain during single freeze-thaw cycles. In contrast to previous studies, both partially (50%) and highly (90%) water-saturated samples display significant deformation during freeze-thaw cycles. This indicates that rapid freezing in a non-uniformly sized pore space can cause damage if only a portion of the pores is fully saturated. Compressive and tensile strength of highly saturated samples decreases by approximately 40 per cent and 95 per cent, respectively, over 17 freeze-thaw cycles. Porosity increases by 80 per cent after three cycles and only by another 30 per cent in the next 14 cycles, indicating rock fatigue by destruction of the grain bonds. We introduce a generalised fatigue damage model, capable of comparing fatigue damage under different weathering regimes and in different rock types. We show how repeated frost action systematically causes rock fatigue and a major decrease in compressive and tensile strength of rocks.

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Cyclic Plasticity and Low Cycle Fatigue Life in Variable Amplitude Loading

Cited by 57 publications

References 9 publications

Analysis of the Effective and Internal Cyclic Stress Components in the Inconel Superalloy Fatigued at Elevated Temperature

Analysis of the Effective and Internal Cyclic Stress Components in the Inconel Superalloy Fatigued at Elevated Temperature

Mechanical Properties of BNM at Ambient Temperature

Quantifying Rock Fatigue and Decreasing Compressive and Tensile Strength after Repeated Freeze‐Thaw Cycles

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