scholarly journals The Relationship between Fatigue Crack Propagation Property and Fatigue Life at Elevated Temperatures on P/M Ni-base Superalloy, AF 115. Through Fatigue and Creep Strain Energy Parameters, .DELTA.Wf and .DELTA.Wc.

1999 ◽  
Vol 65 (634) ◽  
pp. 1349-1356
Author(s):  
Toshinori YOKOMAKU ◽  
Seiya FURUTA ◽  
Kenji IWAI
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Crack Propagation ◽  
Creep Strain ◽  
Fatigue Crack Propagation ◽  
Strain Energy ◽  
Elevated Temperatures ◽  
Propagation Property ◽  
The Relationship ◽  
Base Superalloy

Comparison of the Fatigue Crack Propagation Resistance of α+β and β Titanium Alloys

2008 ◽  
Vol 378-379 ◽  
pp. 117-130
Author(s):  
Matteo Benedetti
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Titanium Alloys ◽  
Fatigue Crack Propagation ◽  
Propagation Resistance ◽  
Microstructural Parameters ◽  
Crack Propagation Resistance ◽  
Microcrack Propagation ◽  
Small Cracks ◽  
The Relationship

The present paper tries to summarize the relationship between microstructure, extrinsic mechanisms and fatigue crack propagation resistance of α+β and β titanium alloys. Emphasis is placed on microstructural parameters, which can be varied by processing, and their effects on the material inherent fracture properties, governing the resistance against microcrack propagation. Moreover, the resistance against macrocracks as well as small cracks in the presence of notch plasticity has been discussed on the basis of secondary extrinsic mechanics such as crack front geometry, crack bridging and crack closure.

Dynamic Property and Fatigue Crack Propagation Research on Tire Sidewall and Model Compounds

1985 ◽  
Vol 58 (4) ◽  
pp. 785-805 ◽  
Author(s):  
D. G. Young
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Strain Rate ◽  
Fatigue Crack Propagation ◽  
Strain Energy ◽  
Laboratory Data ◽  
Sample Thickness ◽  
Strain Level ◽  
Strain Rate Effects ◽  
Rate Effects

Abstract Research was conducted to define appropriate compound loading conditions and energy parameters required to properly control and analyze fatigue crack propagation experiments for tire sidewall applications. The effects of strain level, pulse frequency, overall cycle frequency, sample thickness, and oven temperature were screened, and strain level was shown to be the dominant variable in the region of interest. Designed experiments further confirmed that frequency (i.e., strain rate) effects upon strain energy are small at normal rates of tire deformation (equivalent to 40 Hz). However, at typical laboratory test frequencies (≤5 Hz), strain rate effects on strain energy are large, and the differences vs. results under tire conditions depend heavily on polymer type as well as test temperature. Thus, the use of strain level, strain rate, and temperature conditions which simulate the tire service environment are critical to give representative results in laboratory testing. A constitutive equation was defined which provides an excellent model for strain energy in pure (or simple) shear as a function of the principal extension ratio (i.e., strain level) at constant frequency. Therefore, computer modeling of such experiments appears straightforward using an on-line minicomputer. Fatigue crack propagation studies showed major effects of pure-shear sample thickness, processing prior to molding, different types of reference compounds, and different polymer types. Halobutyl compounds and halobutyl/EPDM/NR blends were shown to provide superior FCP resistance at a given strain or strain energy level. These results were consistent with earlier tire and laboratory data.

Microstructurally small fatigue crack propagation and retardation at grain boundary in a polycrystalline Ni-base superalloy

2018 ◽  
Vol 2018 (0) ◽  
pp. OS0819
Author(s):  
Masafumi MATSUNAMI ◽  
Motoki SAKAGUCHI ◽  
Hideaki KANEKO ◽  
Takanori KARATO ◽  
Kenta SUZUKI ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Grain Boundary ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Small Fatigue Crack ◽  
Base Superalloy

The Development of Fatigue Crack Propagation Models for Engineering Applications at Elevated Temperatures

1975 ◽  
Vol 97 (4) ◽  
pp. 289-297 ◽  
Author(s):  
B. Tomkins
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Elevated Temperatures ◽  
Failure Process ◽  
Propagation Models ◽  
Creep Fatigue ◽  
Creep Cavitation ◽  
Crack Propagation Process

The value of modelling the fatigue crack propagation process is discussed and current models are examined in the light of increasing knowledge of crack tip deformation. Elevated temperature fatigue is examined in detail as an area in which models could contribute significantly to engineering design. A model is developed which examines the role of time-dependent creep cavitation on the failure process in an interactive creep-fatigue situation.

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