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Affiliation of Author(s):航空学院

Journal:J Vib Shock

Abstract:Based on the torsion spring model and the modified Paris formula, an analytical method was proposed to predict the fatigue life of a cantilever beam with an initial crack under different external temperatures. In the modal analysis process, the temperature module was introduced through the elastic modulus, and the cracked cantilever beam was transformed to two intact elastic beams by using a torsion spring to replace the crack segment; An inherent vibration characteristic equation of the cracked beam would be deduced under different temperatures, and effects of temperatures and crack geometric parameters on the frequency of the cracked beam would be analyzed. In the fatigue life analysis process, the damping loss factor was introduced through the complex elastic modulus. Considering the interaction of the cracked beam vibration and the fatigue crack growth, effects of temperatures, dampings and crack geometric parameters on the fatigue life of the cracked beam would be analyzed based on the modified Paris formula and the timing analysis method. Results indicate: the natural frequency and fatigue life of the cracked cantilever beam gradually decrease with the decreased relative position and the increased relative depth of the crack. And the increase of external temperature leads to the decrease of the natural frequency and fatigue life of the cracked cantilever beam. The fatigue life of the cracked beam gradually increases with the increased damping loss factor. © 2017, Editorial Office of Journal of Vibration and Shock. All right reserved.

ISSN No.:1000-3835

Translation or Not:no

Date of Publication:2017-04-28

Co-author:Ma, Yijiang

Correspondence Author:陈国平