气动环境下结构噪声载荷谱编制方法  

A method for compiling structure sound load spectrum in aerostatic environment

作　　者：王琰[1,2] 郭定文 WANG Yan;GUO Dingwen(Aircraft Strength Research Institute of China,710065 Xi’an,China;Laboratory of Aeronautical Acoustics and Vibration,710065 Xi’an,China)

机构地区：[1]中国飞机强度研究所,西安710065 [2]航空声学与振动航空科技重点实验室,西安710065

出　　处：《应用力学学报》2023年第2期275-281,共7页Chinese Journal of Applied Mechanics

基　　金：航空基金资助项目(No.20181523005)。

摘　　要：目前针对既受气动静压力又受声载荷的结构,试验考核时大部分是静强度与声疲劳寿命分开考核,但是气动静压产生的拉伸平均应力会影响结构的声疲劳寿命,本研究提供一种气动环境下结构噪声载荷谱编制方法,将气动静压对结构寿命的影响等效到声载荷中,便于在实验室中进行疲劳寿命验证。通过有限元研究了气动静压对结构振动特性和响应特性的影响,计算得到了不同压力情况下结构的振动特性,并且得到了气动静压与声载荷联合作用下结构的响应,根据相应材料的随机S-N曲线计算得到不同静压下结构的声疲劳寿命,得出了气动静压达到一定值会严重影响结构声疲劳寿命的结论。随后利用修正Goodman公式将平均应力非零状态的动应力转化为零平均应力时的动应力,然后根据损伤等效关系将气动静压对结构寿命的影响等效到声载荷中。研究给出了气动环境下结构噪声载荷谱编制方法。Currently,for structures subjected to both aerostatic pressure and sound load,most verification tests of static strength and acoustic fatigue life in the laboratory are separated.However,the average tensile stress generated by aerostatic pressure will affect the acoustic fatigue life of the structure.This paper provides a method for compiling the structure sound load spectrum in aerostatic environment,which equals the influence of aerostatic pressure on the structure lifetime into the sound load,which is convenient for the acoustic fatigue life verification in the laboratory.First,the influence of aerostatic pressure on the vibration characteristics and stress response characteristics of the structure is studied by finite element method.Then the vibration characteristics of the structure under different pressures are calculated,and the stress response of the structure under the combined action of aerostatic pressure and sound load is obtained.Finally,according to the random S-N curve of the corresponding material,the acoustic fatigue life of the structure under different static pressures are calculated.We concluded that when the aerostatic pressure reaches a certain value,it will seriously affect the acoustic fatigue life of the structure.Then the modified Goodman formula is used to convert the dynamic stress of the non-zero mean stress state into the dynamic stress of zero mean stress.The effect of aerostatic pressure on the life of the structure is equal to the sound load according to the damage equivalent relationship.The research provides a method for compiling the structure sound load spectrum in aerostatic environment.

关 键 词：平均应力 声疲劳 载荷谱 损伤等效 修正Goodman公式 

分 类 号：V215.1[航空宇航科学与技术—航空宇航推进理论与工程]