A Four-Bearing Fatigue Life Test Rig

2009 ◽  
pp. 206-206-13
Author(s):  
RA Hobbs
Keyword(s):  
Fatigue Life ◽  
Life Test ◽  
Test Rig ◽  
Fatigue Life Test

Correlated and Coherent Analysis Based on Vibration Data of Fatigue Life Test Rig for Ball with Three Point Contact

2012 ◽  
Vol 503-504 ◽  
pp. 1078-1081
Author(s):  
Jing Ling Zhou ◽  
Yu Jing Li ◽  
Wei Ming Zuo ◽  
Wei Nan Zhu ◽  
Ru Song Ren
Keyword(s):  
Fatigue Life ◽  
Function Analysis ◽  
Point Contact ◽  
Life Test ◽  
Test Rig ◽  
Vibration Data ◽  
Auto Correlation ◽  
Input Signals ◽  
The Impact ◽  
Fatigue Life Test

The exciting input signals of the parts in a fatigue life test rig for ball with three point contact and the system’s output signals were analyzed by auto-correlation and cross-correlation with MATLAB software, which eliminated the impact of noise to a certain extent and got the response signals of same frequencies caused by exciting input signals. Finally, the result showed that the text rig was linear by coherent function analysis, which provided the theory basis for modal and dynamic analysis further.

Effect of High Pressure Gaseous Hydrogen on Fatigue Properties of SUS304 and SUS316 Austenitic Stainless Steel

2018 ◽  
Author(s):  
Takashi Iijima ◽  
Hirotoshi Enoki ◽  
Junichiro Yamabe ◽  
Bai An
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
Fatigue Life ◽  
Austenitic Stainless Steel ◽  
Room Temperature ◽  
Hydrogen Gas ◽  
Gaseous Hydrogen ◽  
Life Test ◽  
Air Atmosphere ◽  
Fatigue Life Test

A high pressure material testing system (max. pressure: 140 MPa, temperature range: −80 ∼ 90 °C) was developed to investigate the testing method of material compatibility for high pressure gaseous hydrogen. In this study, SSRT and fatigue life test of JIS SUS304 and SUS316 austenitic stainless steel were performed in high pressure gaseous hydrogen at room temperature, −45, and −80 °C. These testing results were compared with those in laboratory air atmosphere at the same test temperature range. The SSRT tests were performed at a strain rate of 5 × 10−5 s−1 in 105 MPa hydrogen gas, and nominal stress-strain curves were obtained. The 0.2% offset yield strength (Ys) did not show remarkable difference between in hydrogen gas and in laboratory air atmosphere for SUS304 and SUS316. Total elongation after fracture (El) in hydrogen gas at −45 and −80 °C were approximately 15 % for SUS304 and 20% for SUS316. In the case of fatigue life tests, a smooth surface round bar test specimen with a diameter of 7 mm was used at a frequency of 1, 0.1, and 0.01 Hz under stress rate of R = −1 (tension-compression) in 100 MPa hydrogen gas. It can be seen that the fatigue life test results of SUS304 and SUS316 showed same tendency. The fatigue limit at room temperature in 100 MPa hydrogen gas was comparable with that in laboratory air. The room temperature fatigue life in high pressure hydrogen gas appeared to be the more severe condition compared to the fatigue life at low temperature. The normalized stress amplitude (σa / Ts) at the fatigue limit was 0.37 to 0.39 for SUS304 and SUS316 austenitic stainless steels, respectively.

scholarly journals A Study on Failure Analysis and High Performance of Hydraulic Servo Actuator

2020 ◽  
Vol 10 (21) ◽  
pp. 7451
Author(s):  
Yong-bum Lee ◽  
Jong-won Park ◽  
Gi-chun Lee
Keyword(s):  
Fatigue Life ◽  
Accelerated Life Testing ◽  
Test Equipment ◽  
Life Testing ◽  
Life Test ◽  
Accelerated Life ◽  
Servo Actuator ◽  
Hydraulic Servo ◽  
Automotive Parts ◽  
Fatigue Life Test

Hydraulic servo actuator is used as the core actuator in tensile compression fatigue life test equipment as it operates the micro displacement very precisely at a high frequency and can be used continuously for a long period of time. Recently, the life expectancy of automobiles has been extended, the load conditions of accelerated life testing on auto parts have been increased, and the life test time and number of tests have increased significantly in order to secure the reliability of the guaranteed life of produced vehicles. Therefore, hydraulic servo actuators mounted on accelerated life testing equipment for automotive parts are essential for much higher performance and a longer life than those tested. However, small- and medium-sized companies that supply test equipment for the fatigue life of auto often fail to develop technology due to a lack of research personnel and the development budget compared to the capabilities of large automobile manufacturers, resulting in frequent breakdowns due to the technical overload of test equipment. In this study, servo actuators were used to test automotive parts, with a maximum output of 2 ton, a maximum frequency of 3.3 Hz and a maximum displacement of 50 mm. The hydraulic servo actuator, which was installed in the tensile compression fatigue life test equipment, failed to operate normally at the site, and by analyzing it, we realized this resulted from the heat generation of insulation compression due to the accumulation of air and gas into the hydraulic oil and the increase in friction due to the deterioration of flow. A static pressure bearing was adopted as a design change to improve the root cause for this failure mode, and a very high level of geometric concentricity was secured by inserting concentric tubes outside the labyrinth seal type piston. The newly designed and manufactured actuator is the result of research that has achieved a semi-permanent long life and improved performance up to 100 Hz by non-contact operation.

Analysis of Non-Standard Gear Contact Fatigue Life

2013 ◽  
Vol 300-301 ◽  
pp. 1227-1230
Author(s):  
Ying Qiang Xu ◽  
Jian Hua Zhao ◽  
Zu Heng Shi
Keyword(s):  
Fatigue Life ◽  
Fatigue Testing ◽  
Contact Fatigue ◽  
Testing Time ◽  
The Finite Element Method ◽  
Life Test ◽  
Contact Fatigue Life ◽  
Gear Contact ◽  
Fatigue Life Test ◽  
Test Process

A model of gear contact has been established based on Hertz theory in this thesis, Analysis of non-standard gear contact fatigue life test process . For ha* take 1,1.15,1.25 and c* take 0.25,0.5 respectively ,the gear generates contact fatigue failure, then calculate the meshing ratio under different tooth high coefficients, and gear pairs state with fatigue testing time by the finite element method and orthogonal test. These data are compared with the results of specific experiments verified. They description that tooth height coefficients and headspace coefficients change have a great impact on gear contact fatigue life.

scholarly journals Fatigue Life Calculation Method and Experimental Study of the Multiple Corrugated Diaphragm Coupling

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Angang Cao ◽  
Chunhua Ding ◽  
Wei Li ◽  
Zhiyong Zhang
Keyword(s):  
Fatigue Life ◽  
Working Conditions ◽  
High Power ◽  
Element Model ◽  
High Power Density ◽  
Life Test ◽  
High Torque ◽  
Corrugated Diaphragm ◽  
Approximate Result ◽  
Fatigue Life Test

The multiple corrugated diaphragm (MCD) coupling is a new flexible coupling developed based on the diaphragm and diaphragm disc coupling. Compared to traditional couplings, the MCD coupling has the advantages of high torque diameter, high torque weight, and high compensation capability. It is more suitable for high power speed and high power density working conditions. The MCD coupling is subjected to axial, angular, torque, and centrifugal force loads. The fatigue failure caused by alternating stress is the primary failure mode of the coupling. The fatigue life of the MCD coupling cannot be accurately calculated because of the complexity of the force in operation. Some theoretical simplifications can only obtain the approximate result. In this paper, a parameterized finite element model of the MCDs is established. A method for calculating the fatigue safety factor of the MCD coupling is proposed based on a modified Goodman curve to know the design of the MCD coupling. The feasibility of this method is verified by the fatigue life test of the coupling.

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