Nondestructive Simulation Of Impact Source Location Test Signal On The Spacecraft Cabin By Space Debris

The impact events of space debris are very frequent,causing great harm.For manned pressurized cabin,the impact of collision is more serious.A kind of onboard monitoring system based on acoustic emission technology can be used to monitor the impact events of space debris,and to locate and evaluate the damage source.The damage location to the impact source is an important functional module of onboard monitoring system of manned pressurized cabin.Before the launch of the spacecraft,the need for ground validation of the functional modules,and strictly guaranteed not to cause of the manned cabin any mechanical damage(abrasion or pit).Based on this requirement,a nondestructive simulation method for space debris impact signals is developed for ground detection,on orbit perceptual subsystem completeness,and verification of location accuracy of impact source localization function modules.The hypervelocity impact signal mainly includes S0,A0,S2 three mode components,which S0 mode wave propagation speed fastest.The onboard monitoring system is to obtain the arrival time of the signal S0 mode by the threshold method,and use the virtual wavefront algorithm to locate the damage source.In this paper,the method of S0 mode excited by piezoelectric probe is used to simulate the position signal,and the method of numerical simulation and experimental verification is used to do the research.First,this paper established the piezoelectric probe excitation signal of finite element simulation model of acoustic emission using ABAQUS simulation software,according to the selected by the narrowband sine wave signal Hanning modulation window as the excitation signal for simulation analysis,reliable for S0 mode excitation source location acquisition.Secondly,the two-dimensional model of stiffened panel of aluminum alloy is established by using ABAQUS simulation software,and the propagation law of S0 modal signals in the reinforced structure of spacecraft is studied.According to the simulation analysis,aiming at the problem that the amplitude of the S0 modal signal is low under the single point excitation,a technical scheme is proposed to enhance the analog signal amplitude and improve the positioning accuracy by means of array excitation.Finally,for the large area Aluminum Alloy plate and stiffened plate experiments were carried out to study the excitation signal source localization lossless piezoelectric probe,using the single point excitation in Aluminum Alloy plate vertical excitation of Lamb wave,S0 modal simulation of space debris impact acoustic emission signals,far transmission distance of analog signal was measured and simulated experiment of impact source in the effective monitoring range,experiments verify the effectiveness of the piezoelectric straight probe excitation S0 mode signal simulation method to locate the source of the impact.This paper presents a concept of "equivalent excitation loop",the positioning of the experiment uses array excitation model of equivalent excitation loop ",the experiment verified that the" equivalent excitation loop "compared with the method of single point excitation can meet the monitoring area larger and higher positioning accuracy.