基于应力概率密度和功率谱密度法的随机声疲劳寿命预估方法研究

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振动与冲击 ›› 2010, Vol. 29 ›› Issue (1) : 162-165.

论文

基于应力概率密度和功率谱密度法的随机声疲劳寿命预估方法研究

沙云东;郭小鹏;张军

作者信息 +

Research on the random sonic fatigue life prediction based on the stress probability density and power spectrum density method.

Sha Yundong;Guo Xiaopeng;Zhang jun

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文章历史 +

摘要

针对航空发动机燃烧室火焰筒结构的声疲劳问题，研究了一种用于随机载荷下结构疲劳寿命预估的有效方法。首先，对薄壁结构在随机载荷作用下的Von Mises应力过程的概率分布作了研究，给出了应力峰值概率密度函数的表达式。基于Miner线性理论，提出了基于应力概率密度和功率谱密度法的随机声疲劳寿命预估方法，并建立了疲劳寿命预估模型。以某型航空发动机燃烧室火焰筒结构为例，在采用耦合的有限元和边界元方法计算出随机声疲劳应力基础上，应用所建立的模型进行了疲劳寿命估算，并对计算结果进行了宽带修正。结果表明，该方法对航空薄壁结构随机疲劳寿命分析具有实用性。

Abstract

As to the sonic fatigue problem of an aero-engine combustor liner structure, an effective method for predicting the fatigue life of a structure under random loadings is studied. Firstly, the probability distribution of Von Mises Stress of thin-walled structure under random loadings is studied, as a result, the representation of the peak stress probability density is given here. Based on the Miner linear theory, the method for predicting the random sonic fatigue life based on the stress probability density and power spectrum density is proposed, and the modal for fatigue life prediction is constructed. As an example, an aero-engine combustor liner structure is considered. Based on the random sonic fatigue stress is calculated by using the coupled FEM and BEM method, the fatigue life is estimated by using the constructed modal. And considering the influence of the wide frequency band, the calculated results are modified. The results show that, the methods presented in this paper are practical for the random fatigue life analysis of the aeronautical thin-walled structures.

导出引用

沙云东;郭小鹏;张军. 基于应力概率密度和功率谱密度法的随机声疲劳寿命预估方法研究[J]. 振动与冲击, 2010, 29(1): 162-165

Sha Yundong;Guo Xiaopeng;Zhang jun . Research on the random sonic fatigue life prediction based on the stress probability density and power spectrum density method.[J]. Journal of Vibration and Shock, 2010, 29(1): 162-165