Stabilization and programming of the static load during fatigue tests under an asymmetric loading cycle and high temperatures

1977 ◽  
Vol 9 (5) ◽  
pp. 623-626
Author(s):  
V. P. Golub ◽  
I. I. Ishchenko ◽  
B. N. Sinaiskii ◽  
A. D. Pogrebnyak
Keyword(s):  
High Temperatures ◽  
Static Load ◽  
Fatigue Tests ◽  
Loading Cycle ◽  
Asymmetric Loading

scholarly journals S235JRC+C Steel Response Analysis Subjected to Uniaxial Stress Tests in the Area of High Temperatures and Material Fatigue

2021 ◽  
Vol 13 (10) ◽  
pp. 5675
Author(s):  
Josip Brnic ◽  
Marino Brcic ◽  
Sebastian Balos ◽  
Goran Vukelic ◽  
Sanjin Krscanski ◽  
...  
Keyword(s):  
High Temperatures ◽  
Room Temperature ◽  
Uniaxial Stress ◽  
Fatigue Tests ◽  
Experimental Investigations ◽  
Response Analysis ◽  
Stress Tests ◽  
Staircase Method ◽  
Mechanical Fatigue ◽  
Proper Material

Knowledge of the properties and behavior of materials under certain working conditions is the basis for the selection of the proper material for the design of a new structure. This paper deals with experimental investigations of the mechanical properties of unalloyed high quality steel S235JRC + C (1.0122) and its behavior under conditions of high temperatures, creep and mechanical fatigue. The response of the material at high temperatures (20–700 °C) is shown in the form of engineering stress-strain diagrams while that at creep behavior (400–600 °C) is shown in the form of creep curves. Furthermore, based on uniaxial fully reversed mechanical fatigue tests (R=−1), a stress-life (S-N) fatigue diagram has been constructed and the fatigue (endurance) limit of the material is calculated The experimentally determined value of tensile strength at room temperature is 534 MPa. The calculated value of the fatigue limit, also at room temperature, using the modified staircase method and based on the mechanical fatigue tests data, is 202 MPa. With regard to creep resistance, steel 1.0122 can be considered creep-resistant only at a temperature of 400 °C and at an applied stress not exceeding 50% of the yield strength corresponding to this temperature.

Cyclic Symmetric Analysis of Fabricated Gear Wheels

1989 ◽  
Author(s):  
V. Ramamurti ◽  
M. Subramaniam ◽  
B. Shanker
Keyword(s):  
Static Load ◽  
Moving Load ◽  
Gear Wheel ◽  
Spur Gear ◽  
Asymmetric Loading ◽  
Computer Aided ◽  
Cyclic Symmetric ◽  
Gear Wheels ◽  
State Stress ◽  
The Web

Abstract A computer aided method of analysis of the web portion of a spur gear is presented. The cyclic symmetric concept is used for solving the problem of the steady state stress analysis (asymmetric loading) when the gear is subjected to a concentrated edge load due to the mating tooth. The effect of cut-outs in the web is studied. The response of the web to a moving load is investigated. The ratio of the forcing frequency to the fundamental frequency of the gear wheel being small, the moving load is approximated as a static load acting at different points. The influence of radial ribs on the behaviour of the gear is also studied.

EVALUATION OF CREEP-FATIGUE LIFE BY FRACTION OF CAVITY AREA

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4237-4242
Author(s):  
BUMJOON KIM ◽  
BYEONGSOO LIM
Keyword(s):  
Fatigue Life ◽  
Base Metal ◽  
Gas Turbines ◽  
Cyclic Load ◽  
Static Load ◽  
Hold Time ◽  
Fatigue Tests ◽  
Creep Fatigue ◽  
High Temperature Components ◽  
Main Steam

The components of power plant such as main steam pipe and gas turbines are operated under static and cyclic load conditions. As the period of static load increases, the service life of these components decreases. Generally, the increase of cyclic load results in fatigue damage and the increase of static load period results in the metallurgical degradation by the effect of creep. Under the creep-fatigue interaction, cavities cause rapid degradation of material and decreases the creep-fatigue life of high temperature components. In this paper, creep-fatigue tests were performed to investigate the relationship between the cavity and creep-fatigue life under various tensile hold times. Test materials were HAZ and base metal of P122 (12 Cr -2 W ) alloy weldment. The effect of hold times on the cavity damage was examined and the fraction of cavity area was analyzed. From the linear relationship of Fca (fraction of cavity area) and experimental life, a new parameter for life evaluation, Fca, was introduced and the creep-fatigue life was predicted by Fca. Good agreement was found between experimental and predicted life. Under the same hold time condition, the Fca of HAZ was greater than that of base metal while the creep-fatigue life of HAZ was shorter than that of base metal.

scholarly journals EXPERIMENTAL STUDY ON POST-BUCKLED COMPOSITE SINGLE-STRINGER SPECIMENS WITH INITIAL DELAMINATION UNDER FATIGUE LOADS

2021 ◽  
Author(s):  
ANTONIO RAIMONDO ◽  
JAVIER PAZ MENDEZ ◽  
CHIARA BISAGNI
Keyword(s):  
Static Load ◽  
Compressive Load ◽  
Fatigue Tests ◽  
Load Level ◽  
Image Correlation ◽  
Compressive Behavior ◽  
Fatigue Load ◽  
Out Of Plane ◽  
Post Buckling ◽  
Correlation System

The fatigue damage tolerance of a composite stiffened structure in post-buckling conditions is experimentally investigated in this work. Single-stringer specimens with an initial delamination, artificially created during the manufacturing process, are tested under cyclic compressive load. Six nominally identical specimens are manufactured: two tested under quasi-static load to understand the compressive behavior of the structure and four under fatigue load cycling between pre- and post-buckling conditions at two different maximum loads. During the tests, digital image correlation system and ultrasonic C-scan are adopted to follow the evolution of the out-of-plane displacements and the propagation of the delamination. Depending on the load level, the delamination starts to grow already in the first cycle or after a few thousand cycles, but in both cases the propagation is fast at the beginning, then slows down gradually. The fatigue tests are interrupted after 150,000 cycles and the specimens are subjected to quasi-static compressive load to evaluate the residual strength of the structure.

A method of examining cyclic characteristics of creep-resisting materials at high temperatures in dual-frequency asymmetric loading

1987 ◽  
Vol 19 (7) ◽  
pp. 1022-1026
Author(s):  
B. N. Sinaiskii ◽  
V. P. Butseroga ◽  
V. A. Gorodetskii ◽  
G. K. Skonechnykh
Keyword(s):  
High Temperatures ◽  
Dual Frequency ◽  
Creep Resisting Materials ◽  
Asymmetric Loading

Fatigue Behavior of Metal-Packaged Regenerated Fiber Bragg Grating Strain Sensors at High Temperatures: A Preliminary Study

2019 ◽  
Vol 795 ◽  
pp. 352-357
Author(s):  
Hao Xu ◽  
Yun Tu ◽  
Ya Li Wang ◽  
Shan Tung Tu
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Fiber Bragg Grating ◽  
High Temperatures ◽  
Spectral Response ◽  
Fatigue Tests ◽  
Strain Sensors ◽  
Bragg Grating ◽  
Bragg Wavelength ◽  
Integrity Assessment

Regenerated Fiber Bragg grating (RFBG) sensors exhibit tremendous growth in recent years and could be widely used for measuring strains and for structural integrity assessment of components operated at high-temperature if critical issues (fatigue life, interface integrity, etc.) are addressed. For the determination of fatigue life of metal-packaged RFBG strain sensors at high temperatures, tensile fatigue tests are performed on the sensors. The preliminary results show that the sensors exhibit good linearity and repeatability, and rare sensitivity change under cyclic tension loading when exposed to constant high temperature up to 500 °C, without obvious variations in the spectral response. The rupture of the optical fibers is the major cause of fatigue failure of the sensors. The sensors subjected to lower test strain have greater fatigue life. A rapid decrease in Bragg wavelength is observed at the beginning of the fatigue tests followed by stabilization of the Bragg wavelength. These results indicate that the sensors are the promising candidates for health monitoring of structures subjected to cyclic loads at high temperatures.

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