RIT-22 Ion Propulsion System: 5000h Endurance Test Results and Life Prediction

Author(s):  
Hans Leiter ◽  
Ralf Kukies ◽  
Rainer Killinger ◽  
Lisa Bonelli ◽  
Simone Scaranzin ◽  
...  
2020 ◽  
Author(s):  
Aodi Yu ◽  
Hong-Zhong Huang ◽  
Yan-Feng Li ◽  
He Li ◽  
Ying Zeng

Abstract Mean stress has a great influence on fatigue life, commonly used stress-based life prediction models can only fit the test results of fatigue life under specific stress ratio or mean stress but cannot describe the effect of stress ratio or mean stress on fatigue life. Smith, Watson and Topper (SWT) proposed a simple mean stress correction criterion. However, the SWT model regards the sensitivity coefficient of all materials to mean stress as 0.5, which will lead to inaccurate predictions for materials with a sensitivity coefficient not equal to 0.5. In this paper, considering the sensitivity of different materials to mean stresses, compensation factor is introduced to modify the SWT model, and several sets of experimental data are used for model verification. Then, the proposed model is applied to fatigue life predictions of rolling bearings, and the results of proposed method are compared with test results to verify its accuracy.


2016 ◽  
Vol 158 (B1) ◽  
Author(s):  
M Geor ◽  
S Hooper ◽  
S Tamakai ◽  
A P R Taylor

The Linear Induction Motor (LIM) has been employed as an actuator in conveyers and more recently aircraft launches, and some work has been done on LIMs with a curved secondary reaction plate. This paper presents a working model of a marinised LIM-boat system, with underwater stator operating the hull of a boat which acts as reaction plate. The LIM stator is shown to propel the boat through the water, and that with certain reaction plate metals it will track over the stator coils and therefore be controllable in both direction and speed. Test results for differing coils and reaction plate combinations are provided.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1587 ◽  
Author(s):  
Krzysztof Kluger ◽  
Aleksander Karolczuk ◽  
Szymon Derda

This study presents the life-dependent material parameters concept as applied to several well-known fatigue models for the purpose of life prediction under multiaxial and non-zero mean loading. The necessity of replacing the fixed material parameters with life-dependent parameters is demonstrated. The aim of the research here is verification of the life-dependent material parameters concept when applied to multiaxial fatigue loading with non-zero mean stress. The verification is performed with new experimental fatigue test results on a 7075-T651 aluminium alloy and S355 steel subjected to multiaxial cyclic bending and torsion loading under stress ratios equal to R = −0.5 and 0.0, respectively. The received results exhibit the significant effect of the non-zero mean value of shear stress on the fatigue life of S355 steel. The prediction of fatigue life was improved when using the life-dependent material parameters compared to the fixed material parameters.


2000 ◽  
Author(s):  
Rainer Killinger ◽  
Helmut Bassner ◽  
Johann Mueller ◽  
Ralf Kukies

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