摘要
脉冲风洞测力系统传力特性研究有助于评价风洞测力试验数据的准确性。目前,该类研究鲜见报道。针对力在测力系统中的传递难以测量及系统结构对传感器安装位置限制的特点,提出了一种基于有限元仿真的风洞测力系统传力特性分析方法。基于参数辨识的方法建立系统整机动力学模型,并对整机进行了模态试验,验证了该有限元模型的准确性;基于飞行动力学理论选取飞行器模型重心与天平间的传力特性来描述整机传力特性;在此基础上,进行谐响应分析,获得力在飞行器模型重心与天平浮动框间的传递特性;将飞行器模型所受气动力等效成模型重心处的集中力,并对其进行傅里叶变换,展开成一系列谐波力信号,基于重心-天平浮动框的传递特性计算各谐波力信号传递至天平浮动框后的大小;以天平测试分辨率为依据,筛选出未被天平识别的谐波力,并计算其能量占总体信号能量的百分比,以此来评估测力系统传力特性的好坏。分析结果表明,测力系统在轴向、径向与垂向具有良好的传力特性,能保证测力试验数据的可靠性。该方法可为测力系统测试精度预测与及测试误差影响因素分析提供技术支持,具有广阔的应用前景。
Studying force transmission characteristics of force-measuring system in impulse combustion wind tunnel can help to improve the accuracy of evaluating wind tunnel force measurement data. At present,this kind study is rare. A method for wind tunnel force-measuring system’s force transmission characteristics analysis based on the finite element simulation was proposed. Firstly,the dynamic model of the force-measuring system was established based on the parametric recognition method. The correctness of this built finite element model was verified using the system’s modal tests. Secondly,based on the theory of aircraft dynamics,force transmission characteristics between gravity center of an aircraft model and floating frame of a balance were selected to describe the force transmission characteristics of the forcemeasuring system. Then,a harmonic response analysis for the finite element model of the force-measuring system was performed to obtain force transmission characteristics between gravity center of an aircraft model and floating frame of a balance. Thirdly,the aerodynamic force acting on the aircraft model was equivalent to a concentrated force acting on the gravity center of the aircraft model,and the concentrated force was converted into a series of harmonic force components with Fourier transform. Based on the force transmission characteristics between the gravity center of the aircraft model and the floating frame of the balance,a series of harmonic force components were transferred from the gravity center of the aircraft model to the floating frame of the balance and then their new values were obtained. Finally,according to the balance test resolution,the harmonic force component unrecognized by the balance was screened. The ratio of this harmonic force component ’s energy to the total signal energy was calculated to evaluate the force transmission characteristics of the force-measuring system.
作者
李世超
高宏力
刘勃锴
付国强
鲁采江
LI Shichao;GAO Hongli;LIU Bokai;FU Guoqiang;LU Caijiang(School of Mechanical Engineering,Southwest Jiaotong University,Chengdu 610000,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2018年第21期117-125,142,共10页
Journal of Vibration and Shock
基金
国家自然科学基金(51775452)
关键词
脉冲燃烧风洞
测力系统
傅里叶变换
频响函数
传力特性
impulse combustion wind tunnel
force-measuring system
Fourier transform
frequency response function
force transmission characteristics
