Structural Transient Response Analysis Theory And Simulation Based On Statistical Energy Analysis

The rapid development of aerospace technology makes greater demands on the structural design of spacecrafts.Study and analysis on large and complex spacecrafts are increasingly urgent to enable them to achieve better their functionality,among which a main problem lies in the prediction of vibro-acoustic environment,transient impact load and dynamic response.Environmental prediction methods ever developed at present include finite element method,boundary element method,modal analysis,impedance admittance method,power flow method,statistical energy analysis.Statistical energy analysis has enormous advantages over those previous methods on high-frequency problems.Since it is based on the assumption of steady state,it needs to be extended to transient statistical energy analysis to solve transient problems.Firstly Statistical energy analysis(S.E.A.)and transient statistical energy analysis(T.S.E.A.)theories are introduced in this paper,and the two theories are digested and the energy expression in transient statistical energy analysis is deduced considering the case of a two-plate system.Programs are written based on both theories of steady state and transient state,with which steady and transient response of both a two-plate system and a three plate system are evaluated.The results are compared with solution by the existing S.E.A.software VAone.To realize a statistical energy analysis simulation in which the user models a system and inputs parameters,a GUI software Adolphus 1.0 is empoldered for evaluating steady and transient response of S.E.A.systems programmed in MATLAB language based on statistical energy analysis and transient statistical energy analysis,and is successful in its testing.Then some statistical energy analysis parameters of a two-aluminum-honeycomb-plate system are experimentally measured.Energy and Power are obtained by processing the time-domain signals from accelerometers and an impedance head,and on these grounds the damping loss factors and coupling loss factors are calculated.The results are verified through modeling with them in Adolphus.Finally a complex satellite box structure consisting of five experimentally used plates is built in Adolphus,given loads and solved using statistical energy analysis.The same system is established in VAone and given the same steady load,and the solution is compared with Adolphus results.Transient statistical energy analysis is also done.First a load is applied in a certain band equivalent with that in steady-state analysis.Comparison is drawn between the convergence value of transient response and the solution for steady-state analysis.Subsequently a load oscillating in time domain is applied in another band,what follows is the response calculation and analysis.