Random vibration fatigue of structures is intrinsically multiaxial, driven by complex stress states. Non-proportional multiaxial stresses exacerbate fatigue damage compared to proportional stresses. Frequency domain fatigue analysis is generally more efficient for structures operating near natural frequencies. However, handling non-proportional multiaxial stress effects in the frequency domain remains challenging. This paper introduces a data-driven framework that reformulates time domain multiaxial fatigue failure criteria into their frequency domain counterparts, explicitly addressing non-proportional effects. The method introduces a non-proportional correction factor into the power spectral density of equivalent stress, determined through a data-driven approach, converting various time domain multiaxial fatigue criteria into their frequency domain equivalents. Combined with modal decomposition analysis, this approach efficiently evaluates multiaxial vibration fatigue for engineering structures, effectively accounting for non-proportional stress effects.

中文翻译：

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在频域中推广多轴振动疲劳标准：数据驱动的方法

结构的随机振动疲劳本质上是多轴的，由复杂的应力状态驱动。与比例应力相比，非比例多轴应力会加剧疲劳损伤。对于在固有频率附近运行的结构来说，频域疲劳分析通常更有效。然而，处理频域中的非比例多轴应力效应仍然具有挑战性。本文介绍了一种数据驱动框架，该框架将时域多轴疲劳失效准则重新表述为频域对应准则，明确解决了非比例效应。该方法将非比例校正因子引入到等效应力的功率谱密度中，通过数据驱动的方法确定，将各种时域多轴疲劳标准转换为其频域等效标准。结合模态分解分析，该方法可以有效评估工程结构的多轴振动疲劳，有效地考虑非比例应力效应。