导航

ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2020, Vol. 41 ›› Issue (2): 223229-223229.doi: 10.7527/S1000-6893.2019.23229

• Solid Mechanics and Vehicle Conceptual Design • Previous Articles     Next Articles

Accelerated random fatigue test design based on stress distribution model

MU Tong1,2, MENG Ge1,2, XIE Liyang1,2, ZHANG Jianbo3, SHI Chaocheng3   

  1. 1. School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819;
    2. Key Laboratory of Vibration and Control of Aero-Propulsion System, Ministry of Education, Shenyang 110819;
    3. Shanghai Aeronautical Material and Structures Testing Co., LTD, Shanghai 201210, China
  • Received:2019-06-19 Revised:2019-09-09 Online:2020-02-15 Published:2019-10-24
  • Supported by:
    National Natural Science Foundation of China Liaoning Joint Fund (U1708255)

Abstract: The two-stage S-N curve is applied to the Dirlik random vibration fatigue life prediction model. The fatigue damage of each stress interval is calculated in segments and superimposed together. Based on the stress amplitude distribution estimated by the Dirlik model, the equivalent relationship between the magnification of excitation and fatigue life under the two-stage S-N curve is deduced. A life conversion method of accelerated life test based on the equivalent relationship is proposed, which provides a reference for the determination of stress level for accelerated life tests. The method can be generalized to the multi-stage S-N curve, like the very high cycle fatigue. For the large ratio of small stress amplitude in the random vibration fatigue, the damage computing method of this part is optimized, and the more realistic equivalent relationship between theoretical fatigue life and accelerated life is obtained. The analysis of an example shows that under the two-stage S-N curve, the relationship between stress and life also shows a logarithmic linear relationship of two-stage, which is verified by using the experimental data in the literature.

Key words: random vibration, frequency domain, fatigue life, accelerated test, equivalent relation

CLC Number: