Random Load Identification And Dynamic Response Analysis On High Speed Aircraft

High speed aircraft refers to the long-range cruise aircraft with a Mach number greater than 5.0,which will have a significant impact on operations,transportation and high-altitude exploration.Dynamic environment prediction is the basis and key of spacecraft aircraft design.At present,the development of low-frequency dynamic prediction technology is mature,and high precision results are obtained.But there are problems with high frequency load forecasting.At the same time,the response of hypersonic vehicle structure under random pressure load is also the key to the prediction of dynamic environment.The main research content of this paper is the identification of high frequency load based on statistical energy method and the analysis of random response.This article first elaborated the basic assumptions of the statistical energy,balance of power flow equation is deduced,according to the actual size and properties of the system will split multiple sub system,by solving power flow balance equation to identify the input power of the system.According to the specific load location and the integrity of the subsystem response load identification problem is subdivided into three different situations.The first kind of circumstance is known all subsystem response and load position,the second is all subsystem response known location is unknown,and the third is load position known but some subsystems response unknown.The effectiveness of applying statistical energy method to high frequency load identification is verified by comparing the simulation results of two plate and three plate coupled structures with the test results.Secondly,the dynamic response analysis under random pressure is analyzed.This paper designs and processes a simulated aircraft module segment,obtains the modal characteristics of the module segment and the results of the random response,carries out detailed modeling,analyzes random response of the module segment,discusses different calculation methods,analyzes the influence of frequency points and damping on the experimental results,and obtains the damping and frequency analysis point setting methods applicable to the model.