基于频域法的随机振动疲劳加速试验设计
Random Vibration Fatigue Accelerated Test Design Based on Frequency Domain Methods

基于结构疲劳寿命频域分析法中的Bendat法和Dirlik法，通过理论推导分析证明并建立了随机振动疲劳试验中激励谱量级、响应应力水平和疲劳寿命之间的线性关系式。基于有限元仿真的分析结果，提出了一种利用此等效关系进行加速试验激励谱量级确定的方法。算例表明，该加速方法可缩短试验时间，为改进设计和提高质量等工作提供参考依据。
The structural vibration fatigue test usually takes a long time under actual load excitation, so the accelerated test method is often used instead. The key to accelerated test design lies in establishing the mutual relationships between the different excitation spectrum, response stress and fatigue life. Fatigue life analysis in the frequency domain has the significant advantages of simple calculations, low computational complexity and good engineering practicability. Frequency-domain analysis in particular was the only method that solves the problems of fatigue loading with dynamic characteristics. Based on the Bendat and Dirlik methods and through theoretical derivation, this paper approves and establishes the linear relationships between the three and proposes a new way to determine the excitation spectrum magnitude used in the accelerated test based on the above linear relationships and finite element simulation results. A simulation verifies the feasibility of the proposed method.