Non Destructive Testing & Modal Analysis for Seismic Risk Assessment

Transcription

1 Non Destructive Testing & Modal Analysis for Seismic Risk Assessment INTERFEROMETRIC RADAR & MODAL ANALYSIS SONIC TEST ARIEL A. DEVAL UNIVERSITY OF TEXAS AT ARLINGTON 1

2 INTRODUCTION PROJECT OBJECTIVES TO PERFORM A FINITE ELEMENT ANALYSIS OF THE STRUCTURES IN ORDER TO MATCH THE SPECTRAL RESPONSE IN DYNAMIC ANALYSIS. TO OBTAIN THEORETICAL BACKGROUND ON MODAL ANALYSIS, RADAR INTERFEROMETRY AND ON SITE STRUCTURE CASE STUDIES PROJECT TITLE AIDICO RESEARCH MENTOR AIDICO LABORATORY HAZARD TYPE Non-destructive testing and modal analysis for seismic risk assessment. José Vicente Fuente Monitoring Earthquake 2

3 BACKGROUND & EQUIPMENT SONIC TEST Accelerometer MEMS, Instrumented Impact Hammer, Datalogger IMC Cronos SL-8 for 16 channels 3

4 BACKGROUND & EQUIPMENT SONIC TEST PROCEDURE: 1. SET UP LUGGAGE AND PROGRAM 2. CONNECT MEMS TO LUGGAGE IN CORRECT ORDER 3. ARRANGE MEMS LINEARLY ACROSS THE WIDTH OF THE PILLAR 4. TAKE DISTANCES OF HEIGHT OF PILLAR, WIDTH, AND DEPTH. 5. USE IMPACT HAMMER TO STRIKE THE PILLAR IN A POSITION BETWEEN THE MEMS 6. REPEAT STRIKE WITH IMPACT HAMMER BETWEEN FIRST AND SECOND MEMS AND LAST 2 MEMS. 7. REARRANGE MEMS ON LESS THICK (CENTER) OF THE PILLAR AND REPEAT PROCEDURE. 8. ANALYZE RAW DATA 4

5 BACKGROUND: SONIC TEST BASICS SONIC TEST A type of NON-DESTRUCTIVE testing. Pulse waves are transmitted through a material, in this case reinfoced concrete, to detect internal characteristics and properties of a structure. f = c app /2d SONIC TEST OBJECTIVES To identify the frequencies in order to compare various results from different testing methods. To model the structure under a non-controlled environment.

6 BACKGROUND: SONIC TEST BASICS

7 FFT (random values) Signal Waveform FFT (random values) EXPERIMENTAL RESULTS SONIC TEST 1 & A-Scans of Impact on Sonic Test Time (seconds) Hammer SISM X: Y: X: 1224 Y: 19.5 Spectral Response (FFT) of Sonic Test 01 - SISM02 X: 1865 Y: X: 2032 Y: X: 2523 Y: Frequencies (Hz) SAMPLE CALCULATION Depth=0.96 m From MIRA: C p = 3976 m/s C s = 2385 m/s Use equation F= C app /(2*d) A-Scans of Impact on Sonic Test 02 HAMMER SISM Spectral Response (FFT) of Sonic Test 02 - SISM02 X: 2029 Y: Theoretical Frequencies F=3976/(2*0.96)=2.07 khz F=2385/(2*0.96)=1.24 khz Time of Flight (seconds) X: 1230 Y: Frequencies (Hz) Experimental Frequencies FFT Graphs F=1.23 Hz C app =2*d*F= C s =2*0.96*1230=2361 m/s C p =2*0.96*2029=3895 m/s

8 FFT (random values) EXPERIMENTAL RESULTS SONIC TEST 4 & X: 1182 Y: 32.6 Spectral Response (FFT) of Sonic Test 04 - SISM02 X: 2456 Y: SAMPLE CALCULATION Depth=0.70 m From MIRA: C p = 3976 m/s C s = 2385 m/s Use equation F= C app /(2*d) Frequencies (Hz) Theoretical Frequencies F=3976/(2*0.70)=2.84 khz F=2385/(2*0.70)=1.70 khz Experimental Frequencies FFT Graphs F=1.28 Hz C app =2*d*F= C p =2*0.70*2431=3403 m/s C s =2*0.70*1282=1795 m/s

9 EXPERIMENTAL RESULTS POISSON S RATIO Sample Results: C s =2*0.96*1230=2361 m/s (lateral) C p =2*0.96*2029=3895 m/s (longitudinal) C s =2*0.70*1282=1795 m/s (lateral) C p =2*0.70*2431=3403 m/s(longitudinal) Sonic Test 2 ratio = C s /C p = 2361/3895 = 0.60 ν=(1-(2*0.6^2))/(2-(2*0.6^2)) = 0.21 *Correct Measurement with sensors in thicker section of pillar. Sonic Test 5 ratio = C s /C p = 1795/3403 = 0.31 ν=(1-(2*0.31^2))/(2-(2*0.31^2)) = 0.45 * Not correct measurement.

10 BACKGROUND & EQUIPMENT Interferometric Radar IBIS-FS Image by Interferometric Survey INFEROMETRIC RADAR TEST OBJECTIVES To evaluate and compare the results of the interferometric radar with those of the sonic test. To use the FFT of the measurement points to determine frequencies and displacements of the structure at those points. 10

11 RADAR BASICS RADAR: RADIO DETECTION AND RANGING The radar is able to detect the presence of the object/structure and is able to measure the distance between the aparatus and the object, R. Antenna used in this project, G=23 db

12 TEST OBJECTIVES INFEROMETRIC RADAR TEST OBJECTIVES To evaluate and compare the results of the interferometric radar with those of the sonic test. To use the FFT of the measurement points to determine frequencies and displacements of the structure at those points. 12

13 RADAR EQUIPMENT PROCEDURE: 1. ARRANGE THE RADAR AT A DISTANCE WHERE IT WILL DETECT A REFLECTING POINT OF THE STRUCTURE. 2. SET UP THE GEOMETRY SETTINGS IN THE PC. (DISTANCE, ANGLES, HEIGHT) 3. BEGIN RUNNING IBIS FS AND AIM THE RADAR AT THE REFLECTION POINT. 4. START THE PROJECT FROM THE PC TO SELECT RANGE BINS. 5. ONCE THE RANGE BINS DESIRED ARE SELECTED, BEGIN TO COLLECT DISPLACEMENTS AND FREQUENCIES. 6. TAKE ABOUT 45 MINS OF DATA. 7. PROCESS RAW DATA.

14 IBIS RADAR RADAR EQUIPMENT

15 AIDICO BRIDGE EXPERIMENT Bridge loads: Concrete self-weight = 2500 kg/m 3 Steel self-weight = 7850 kg/m 3 15

16 Projected Displacement [mm/hz] Projected Displacement [mm/hz] Projected Displacement [mm/hz] BRIDGE EXPERIMENT RESULTS dynS Surv Spectrum B ridge Conf 1 Reflector 6.4 m X: 1.26 Y: X: 1.44 Y: Rbin dynS Surv Spectrum Bridge Conf 1 Reflector 8.9 m X: 1.26 Y: Rbin dynS Surv Spectrum B ridge Conf 2 Reflector 6.4 m X: 1.26 Y: Rbin X: 2.16 Y: X: 2.94 Y: X: 1.44 Y: Frequency [Hz] Frequency [Hz] frequency [Hz] Reoccuring Frequency 1.26 Hz 16

17 Projected Displacement [mm/hz] Line of Sight Displacement [mm/hz] BRIDGE EXPERIMENT RESULTS dynS Surv Spectrum Bridge Conf 2 Reflector 7.9 m X: 1.26 Y: Rbin dynS Surv Spectrum Bridge Conf 3 Reflector 5.9 m X: 1.26 Y: Rbin X: 1.44 Y: X: 1.44 Y: Frequency [Hz] Frequency [Hz] Reoccuring Frequency 1.26 Hz 17

18 CONCLUSIONS THE RADAR TEST RESULTS MATCHED THE THEORETICAL AND EXPERIMENTAL RESULTS OF THE SONIC TEST. THE REOCCURING FREQUENCY FOR THE RADAR TEST WAS 1.26 Hz WHICH MATCHED 1.28 HZ FROM THE SONIC TEST. 18

19 CASE STUDY: ANCIENT CHIMNEY INDUSTRIAL BRICK CHIMNEY IN AGOST, SPAIN (NEAR ALICANTE) PROBLEM: FATIGUE BY WIND CAN CAUSE THE CRACK PATTERN APPEARENCE. THE CRACK PATTERN AFFECTS TO THE STRUCTURAL CONDITION. THE STRUCTURAL CONDITION CAN BE ASSESSED BY STRUCTURAL HEALTH MONITORING. HAZARD: CRACKS COULD CAUSE THE CHIMNEY TO COLLAPSE IT IS POSSIBLE TO ASSESS THE STRUCTURAL CONDITION BY DYNAMIC MODAL TEST USING NONCONTACT TECHNOLOGY AS RADAR.

20 CASE STUDY: ANCIENT CHIMNEY The University of Alicante begins the rehabilitation of one of the two ancient clay industrial structures still standing. The objective of the project is to avoid a collapse and reinforce it with glass fibers for a seismic event (earthquake). -Jose Antonio Rico of L Alacanti in Agost Archeological Industrial Monuments Corrosion and Wind factors

21 CASE STUDY: ANCIENT CHIMNEY

22 CHIMNEY EXPERIMENTAL RESULTS INTERFEROMETRIC RADAR DISPLACEMENT AND FREQUENCIES FOR DIFFERENT BINS PERPENDICULAR TO THE OPENING TARGET 18.4 m Displacement ±1.0 mm Frequencies **1.38 Hz TARGET 19.4 m Displacement ±1.2 mm Frequencies **1.36 Hz

23 CHIMNEY EXPERIMENTAL RESULTS INTERFEROMETRIC RADAR DISPLACEMENT AND FREQUENCIES FOR DIFFERENT BINS PERPENDICULAR TO THE OPENING TARGET 20.9 m Displacement ±1.2 mm Frequencies **1.34 Hz TARGET 26.9 m Displacement ±1.0 mm Frequencies **1.32 Hz

24 CHIMNEY EXPERIMENTAL RESULTS INTERFEROMETRIC RADAR DISPLACEMENT AND FREQUENCIES FOR DIFFERENT BINS PARALLEL TO THE OPENING TARGET 13.0 m Displacement ±0.25 mm Frequencies **0.94 Hz TARGET 16.4 m Displacement ±0.6 mm Frequencies **0.94 Hz

25 CHIMNEY EXPERIMENTAL RESULTS INTERFEROMETRIC RADAR DISPLACEMENT AND FREQUENCIES FOR DIFFERENT BINS PARALLEL TO THE OPENING TARGET 19.4 m Displacement ±0.35 mm Frequencies **1.64 Hz TARGET 22.9 m Displacement ±0.25 mm Frequencies **1.64 Hz

26 CHIMNEY EXPERIMENTAL RESULTS INTERFEROMETRIC RADAR DISPLACEMENT AND FREQUENCIES FOR DIFFERENT BINS PARALLEL TO THE OPENING TARGET 26.9 m Displacement ±0.45 mm Frequencies **1.64 Hz

27 NUMERICAL MODEL FOR CHIMNEY COMSOL MULTIPHYSICS PROGRAM Boundary conditions: Footing & Wind Load Wind load: although this is actually a dynamic load for our purpose it was modeled as a static load in order to determine immediate displacement it would cause. Used two types of solvers: Eigenfrequencies & Time Dependent Varying material properties As with many ancient structures, the real properties are unknown so it was useful to solve the problem with different properties Elastic Modulus, E Rigidity Poisson s ratio Damping parameters

28 NUMERICAL MODEL FOR CHIMNEY

29 NUMERICAL MODEL FOR CHIMNEY

30 Solver: Linear Parametric Static Load on X-faces: 1400 N/m2 IT CAN BE SHOWN, THE X- DISPLACEMENT ON THE LOAD FACE IS AROUND 25 MM. THIS RESULT MATCHES WITH EXPERIMENTAL DATA

31 Solver: EigenFrequency Static Load on X-faces: 1400 N/m2 Frequency 1 (flexural on X) = 1.52 Hz

32 Solver: EigenFrequency Static Load on X-faces: 1400 N/m2 Frequency 2 (flexural on Y) = 1.52 Hz

33 Solver: EigenFrequency Static Load on X-faces: 1400 N/m2 Frequency 3 (torsinal 1) = 8.71 Hz

34 Solver: EigenFrequency Static Load on X-faces: 1400 N/m2 Frequency 4 (torsinal 2) = 8.72 Hz

35 Solver: EigenFrequency Static Load on X-faces: 1400 N/m2 Frequency 5 (dilating) = 15.2 Hz

36 Solver: EigenFrequency Static Load on X-faces: 1400 N/m2 Frequency 6 (hybrid tors.&flex) = 20.5 Hz

37 ORTHOTROPIC BRICK MASONRY MATERIAL SIMULATION Modeling with different elastic constants, it is possible to get the experimental different main frequencies in the top of the chimney.

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41 COMPARISON MODEL vs TESTS Solver: Linear Parametric Static Load on X-faces: 1400 N/m2 IT CAN BE SHOWN, THE X- DISPLACEMENT ON THE LOADED FACE IS AROUND 25 MM. THIS RESULT MATCHES WITH EXPERIMENTAL DATA

42 CONCLUSIONS Non-destructive technology supplies accurate experimental data to numerical simulations. Numerical simulation allow the explanation of different results from NDT tests to explain different behaviors depending on material properties. Non-destructive technology allows diagnosis of structural soundness of structures. In this way, future damage, possible collapsing, and hazardous situations can be prevented.

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44 ACKNOWLEDGMENTS THANK YOU MENTOR, JOSEVI! THANKS AIDICO & STAFF! THANKS DR. YAZADANI, UTA, & NSF!