Thermo-Mechanical Fatigue of Mar-M247: Part 1—Experiments

1990 ◽  
Vol 112 (1) ◽  
pp. 68-79 ◽  
Author(s):  
D. A. Boismier ◽  
Huseyin Sehitoglu
Keyword(s):  
Grain Boundary ◽  
Prediction Model ◽  
Life Prediction ◽  
Crack Nucleation ◽  
Mechanical Tests ◽  
Fatigue Tests ◽  
Boundary Crack ◽  
Mechanical Fatigue ◽  
Nickel Based Superalloy ◽  
Life Prediction Model

Isothermal fatigue tests, out-of-phase and in-phase thermo-mechanical fatigue tests were performed on Mar-M247 nickel-based superalloy. The experiments were conducted in the temperature range 500°C to 871°C. Results indicate that the lives differ with strain-temperature phasing and with strain rate. The results of out-of-phase thermo-mechanical tests correspond well with strain-life data of isothermal tests conducted at the peak temperature (871°C). However, the in-phase thermo-mechanical results differed depending on the strain amplitude. Significant surface and crack tip oxidation and gamma prime depletion has been observed based on metallographic and Auger Spectroscopic analyses. These changes were measured as a function of time. The environment induced changes significantly influenced the fatigue lives in isothermal and out-of-phase thermo-mechanical fatigue cases. In these cases transgranular cracking was observed. Grain boundary crack nucleation and grain boundary crack growth dominated the in-phase thermo-mechanical fatigue cases. Based on these observations the requirements for a life prediction model are outlined. The life prediction model and the predictions are given in Part 2 of this paper.

Towards the Development of a Physics-Based Thermo-Mechanical Fatigue Life Prediction Model for a Single Crystalline Ni-Base Superalloy

2014 ◽  
Vol 3 (2) ◽  
pp. 20130049 ◽  
Author(s):  
Robert L. Amaro ◽  
Stephen D. Antolovich ◽  
Richard W. Neu ◽  
Benjamin S. Adair ◽  
Michael R. Hirsch ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Prediction Model ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Single Crystalline ◽  
Mechanical Fatigue ◽  
Base Superalloy ◽  
Life Prediction Model

Microscopic Damage Mechanism of Nickel-Based Superalloy Inconel 738LC Under Creep-Fatigue Conditions

2000 ◽  
Vol 122 (3) ◽  
pp. 315-320 ◽  
Author(s):  
Masato Yamamoto ◽  
Takashi Ogata
Keyword(s):  
Fatigue Life ◽  
Grain Boundary ◽  
Life Prediction ◽  
Grain Boundary Sliding ◽  
Fatigue Tests ◽  
Creep Fatigue ◽  
Boundary Sliding ◽  
Inconel 738Lc ◽  
Life Prediction Model

Creep-fatigue damage in Inconel 738LC was clarified by in-situ observation and a new creep-fatigue life prediction model was proposed based on the mechanism identified. Creep-fatigue tests on standard specimens show that the tensile hold creep-fatigue lives were reduced to 60 to 80 percent and those in the compressive hold condition were reduced to 20 to 40 percent of the fatigue life of the same total strain condition. In-situ creep-fatigue tests on miniature specimens show that grain boundary sliding could be observed under the compressive strain hold condition and under the tensile strain hold condition grain boundary cavity damage and grain boundary sliding were observed. These mechanisms are regarded as the main cause of the damage acceleration under the creep-fatigue loading conditions. Therefore, the new creep-fatigue life prediction model, which is based on the nonlinear damage accumulation method, employed two damage acceleration parameters “dsl” and “dcr,” which represent grain boundary sliding damage and grain boundary cavity damage, respectively. Creep-fatigue lives of the test results were well predicted by the proposed model. [S0094-4289(00)01203-2]

scholarly journals Life Prediction Model of Mineral Admixture Cement Based-Materials under Early Age CO2-Erosion

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 413
Author(s):  
Saisai Wang ◽  
Jian Chen ◽  
Xiaodong Wen
Keyword(s):  
Prediction Model ◽  
Life Prediction ◽  
Experimental Tests ◽  
Mineral Admixture ◽  
Model Parameters ◽  
Influence Coefficient ◽  
Test Pieces ◽  
Cement Based Materials ◽  
Particle Group ◽  
Life Prediction Model

Most of the existing models of structural life prediction in early carbonized environment are based on accelerated erosion after standard 28 days of cement-based materials, while cement-based materials in actual engineering are often exposed to air too early. These result in large predictions of the life expectancy of mineral-admixture cement-based materials under early CO2-erosion and affecting the safe use of structures. To this end, different types of mineral doped cement-based material test pieces are formed, and early CO2-erosion experimental tests are carried out. On the basis of the analysis of the existing model, the influence coefficient of CO2-erosion of the mineral admixture Km is introduced, the relevant function is given, and the life prediction model of the mineral admixture cement-based material under the early CO2-erosion is established and the model parameters are determined by using the particle group algorithm (PSO). It has good engineering applicability and guiding significance.

The construction of the life prediction model of 1N and 4N monopropellant thrusters

2013 ◽  
Author(s):  
Go Fujii ◽  
Daisuke Goto ◽  
Hideshi Kagawa ◽  
Shingo Murayama ◽  
Kenichi Kajiwara ◽  
...  
Keyword(s):  
Prediction Model ◽  
Life Prediction ◽  
Life Prediction Model

Wire Fatigue Models for Power Electronic Modules

2003 ◽  
Author(s):  
Karumbu Nathan Meyyappan ◽  
Peter Hansen ◽  
Patrick McCluskey
Keyword(s):  
Prediction Model ◽  
Life Prediction ◽  
Damage Model ◽  
Cyclic Strain ◽  
Temperature Cycling ◽  
Transformation Model ◽  
Time To Failure ◽  
Flexural Failure ◽  
The Wire ◽  
Life Prediction Model

This paper presents two, semi-analytical, physics-of-failure based life prediction model formulations for flexural failure of wires ultrasonically wedge bonded to pads at different heights. The life prediction model consists of a load transformation model and a damage model. The load transformation model determines the cyclic strain is created by a change in wire curvature at the heel of the wire resulting from expansion of the wire and displacement of the frame. The damage model calculates the life based on the strain cycle magnitude and the elastic-plastic fatigue response of the wire. The first formulation provides quick calculation of the time to failure for a wire of known geometry. The second formulation optimizes the wire geometry for maximum time to failure. These model formulations support virtual qualification of power modules where wire flexural fatigue is a dominant failure mechanism. The model has been validated using temperature cycling test results.

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