温度效应对铝合金壁板高频声振疲劳寿命的影响研究  

Thermal effect on the fatigue life of aluminum panel under high-frequency acoustic excitation

作　　者：王晨[1] 陈海波[1] 王用岩 李孔娟 

机构地区：[1]中国科学技术大学近代力学系中国科学院材料力学行为和设计重点实验室,合肥230027 [2]中国成都飞机设计研究所,成都610000

出　　处：《应用力学学报》2018年第4期701-708,共8页Chinese Journal of Applied Mechanics

基　　金：中国科学院战略性先导科技专项(B类)(XDB22040502)

摘　　要：基于统计能量分析方法,计算了不同温度条件下飞行器铝合金壁板的高频声振响应及均方应力;采用零阶矩应力谱法获得了简化应力功率谱,结合频域疲劳寿命分析方法计算了壁板的高频疲劳寿命。分别研究了温度变化导致结构的刚度、材料S-N曲线变化对铝合金壁板高频疲劳寿命的影响规律。研究结果表明:仅考虑刚度变化时,随着温度升高,危险点响应和均方应力均逐渐减小,进而导致壁板疲劳寿命变长;综合考虑刚度、S-N曲线随温度变化时,温度由20℃升高到100℃或降低至-60℃,均会导致铝合金壁板疲劳寿命显著缩短。高频声振疲劳这一特殊的温度效应,对高超声速飞行器的设计而言是一个新的发现。The high-frequency vibro-acoustic responses and mean square stresses of aircraft aluminum panel under different temperature conditions are analyzed by using the statistic energy analysis. The simplified stress power spectrum of the critical point is obtained by the zero moment stress spectrum method, and then high-frequency fatigue life of the panel is calculated by using the frequency domain fatigue life method. The impact of changes of structural stiffness and S-N curves, caused by temperature variation, on the high-frequency fatigue life of aluminum panel is studied. The analyzed results showed that, when only the stiffness change is considered, the vibro-acoustic response and mean square stress at the critical point decrease gradually with respect to the increasing of temperature, which at last results in longer fatigue life. When both changes for structural stiffness and S-N curves are considered, the fatigue life of aluminum panel become shorter obviously when temperature is raised from 20℃ to 100℃ or reduced to-60℃. The specific temperature effect on the high-frequency fatigue life of aluminum panel is a new finding which deserves paying more attention in the design of hypersonic vehicles.

关 键 词：热效应 飞行器壁板 统计能量分析 高频声振 零阶矩应力谱法 疲劳寿命 

分 类 号：TB123[理学—工程力学]