热声复合环境下薄壁锥壳结构响应计算与疲劳寿命预估  

Response Calculation and Fatigue Life Prediction of Thin-walled Conical Shell Structures under Thermal-acoustic Complex Environment

作　　者：王建 沙云东[2] 杜英杰[1] 顾菘[1] 孙智超 WANG Jian;SHA Yun-dong;DU Ying-jie;GU Song;SUN Zhi-chao(Department of Aircraft Maintenance Engineering,Chengdu Aeronautic Polytechnic,Chengdu 610100,China;Liaoning Key Laboratory of Advanced Test Technology for Aeronautical Propulsion System, Shenyang Aerospace University,Shenyang 110136,China)

机构地区：[1]成都航空职业技术学院航空工程学院,成都610100 [2]沈阳航空航天大学辽宁省航空推进系统先进测试技术重点实验室,沈阳110136

出　　处：《装备环境工程》2018年第12期91-97,共7页Equipment Environmental Engineering

基　　金：四川省教育厅自然科学项目(No.18ZB0057);成都航空职业技术学院自然科学项目(No.061754);四川省科技计划项目(No.2018SZ0357)

摘　　要：目的研究热声复合环境下薄壁锥壳结构的动力学响应与疲劳寿命。方法采用耦合的有限元/边界元法,完成不同热声载荷下的振动应力计算。基于改进的雨流计数法,对不同热声载荷下危险点位置及典型位置的疲劳寿命进行预估。结果屈曲前随温度的增加,薄壁锥壳结构的基频降低,屈曲后在一定温度范围内时,基频增加。薄壁锥壳结构的应力集中主要出现在孔边位置,基频在热声激励响应中起主导作用。低阶固有频率处存在较大峰值,高阶频带范围内的峰值较小,模态密度较高。结论在800～1000℃的温度载荷与强声载荷下,薄壁锥壳结构的疲劳寿命只能维持几个小时,所以在抗声疲劳结构设计中要考虑响应谱的频率结构,及注重结构孔边位置的结构设计。Objective To study dynamic response and fatigue life of thin-walled conical shell structures in a thermal-acoustic complex environment.Methods The coupled finite element/boundary element(FEM/BEM)method was used to calculate the vibration stress under different thermal-acoustic loads.Based on the improved rain flow counting method,the fatigue life of the dangerous points and typical locations under different thermal-acoustic loads were estimated.Results The fundamental frequency of the thin-walled conical shell structure decreased firstly with the increase of the temperature before bending and then increased in certain temperature range after bending.The stress concentration of the thin-walled conical shell structure mainly occurred at the edge of the hole.The fundamental frequency played a dominant role in the thermal-acoustic excitation response.There were large peaks at the low-order natural frequencies and small peaks in the high-order frequency band with high modal density.Conclusion In thermal environment from 800℃to 1000℃,the fatigue life can only be reached for a few hours,when the structures bear the strong acoustic loads.Hence,in the anti-acoustic fatigue structural design,the frequency distribution of the response spectrum should be considered,and it is important to pay more attention to design of structural hole edge.

关 键 词：热声环境 锥壳结构 疲劳寿命 耦合的有限元/边界元 改进的雨流计数法 

分 类 号：V241.3[航空宇航科学与技术—飞行器设计]