宏图厅分会场报告会议

1、Comparative Study on Composite Structures Damage Detection Based on Empirical Wavelet Transform and Sparse Components AnalysisReporter: Shang FukaiSupervisors: Yuan Mei, Dong ShaopengOutline2Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室BackgroundBasic MethodsExperiments & ResultsConclusions

2、3Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室SensorsSensorsActuatorActuators excite structureSurrounding sensors record the transient stress wavesImpacts excite structureSensors record stress wavesActive MonitoringPassive MonitoringBackground4Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构

3、健康监测研究室Acoustic Emission(AE): Passive monitoring for SHMAE signals collected by sensors: mixture of different kinds of damage signals.BackgroundBackground5Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Existing problem: How to analyzing AE signals by a proper signal process approach?Tradition

4、al signal processing methods: FFT Shorts: Unable to separate different AE signals.Aim: Extract every kind of damage signal to detect injuries.More effective methods are required. Sparse Component Analysis(SCA), Empirical Wavelet Transform(EWT).Background6Lab of Embedded System and SHM, BHU 北航 嵌入式系统与

5、结构健康监测研究室Blind source separation(BSS) If MN: Underdetermined blind source separation(UBSS) Main method: Sparse Component Analysis(SCA)Background7Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Empirical Wavelet Transform(EWT): Proposed by J.Gilles, 2013.Real electrocardiogram(ECG) signal and t

6、he modes extracted by EWT.Content8Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室BackgroundBasic MethodsExperiments & ResultsConclusionsBasic Methods9Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室A normal method for UBSS: Sparse component analysis(SCA)Basic Methods10Lab of Embedded Sy

7、stem and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Empirical Wavelet Transform (EWT)Basic Methods11Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Content12Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室BackgroundBasic MethodsExperiments & ResultsConclusionsExperiments & Results13Lab of Embedded Syste

8、m and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Simulated Experiments14Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Experiments & ResultsUBSS ModelThree simulated experiments: mixed instantaneously, mixed with time delay (no reverberation), mixed with time delay (with reverberation).15Lab of Embedded Syst

9、em and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Experiments & ResultsMixed instantaneously16Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Experiments & ResultsMixed instantaneouslySCAEWT17Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Experiments & ResultsMixed with time delay (no reverberation)18L

10、ab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Experiments & ResultsMixed with time delay (no reverberation)SCAEWT19Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Experiments & ResultsComparison of two methods20Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Experiments & ResultsM

11、ixed with time delay (with reverberation).21Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室Experiments & ResultsMixed with time delay (with reverberation).Analyzing results by EWTContent22Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室BackgroundBasic MethodsExperiments & ResultsConclus

12、ions23Lab of Embedded System and SHM, BHU 北航 嵌入式系统与结构健康监测研究室ConclusionsNovel AE signals processing methods based on SCA and EWT have been proposed. Three simulated experiments have been conducted to comparing two methods. Results show that EWT has a better performance than SCA.More experiments on actual AE signals are required to test the performance of SCA and EWT.24Lab of Embedded System and SHM, BHU 北航 嵌入式系