Journal of AE, Volume 25, 2007 (ca. 26 MB) - AEWG

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The observation of the structure during testing and the recorded displacement and rotation data (Fig. 2) reveal that the torsional response almost disappeared and the building displaced along the axis of excitation. The observed damage consisted of cracking in the larger columns and spalling of the concrete cover due to and along the lap-spliced bars at the base of the columns. Cracking also developed at the beam-column joints at the ground and the top floor. During the later stages of the excitation though - and due to the damage inflicted on the larger columns - the torsional response re-appeared, albeit at very low amplitude. Acoustic emission monitoring was performed using a 40-channel PAC-DiSP (PAC, 2001) system. The sensors used were standard PAC resonant type R15I, 150-kHz resonance with 40- dB integral preamplifier. The position of the AE sensors and the points of applied deformation are shown in Fig. 1. Sensor position was selected in such a way to permit linear location along the column height and linear x-y location at the 1 st floor joints. Prior to the test the AE sensors were calibrated and the velocity of the AE signals was calculated in order to achieve the best possible sensor set-up sufficiently covering the areas with expected high AE activity. In addition to that the attenuation of the AE signals was measured, Fig. 3. Acoustic Emission Results Fig. 3. Attenuation of the AE signal in column 2 and 3. Prior to the actual test a preliminary, trial loading was performed at low load levels. The maximum load of the preliminary test was 2% of the load that the building was eventually loaded. The AE activity that was recorded during the preliminary test was relatively low with low energy levels, as presented in Fig. 4. This preliminary test resulted in useful information concerning the background noise of the system as well as for setting up acquisition parameters for the AE system. In addition to that, the activity recorded in columns 1 and 2, due to the friction between the jackets and the concrete frame, was useful during the analysis phase in discriminating genuine AE signals from friction and defining damage evaluation levels. The force exerted by each one of the four actuators is presented in Figs. 5 and 6 (four background plots for actuators 1 to 4, respectively) together with AE energy rate from each column. After jacketing the flexible columns, the building response was mainly uniaxial. The complex nature of loading (cyclic loading with varying amplitude and phase shift between actuators) resulted in complicated structural displacements and render infeasible the direct correlation between the applied loading and the AE activity. The majority of the AE activity, around 98%, is emitted from columns 1 and 2. As can be seen from Figs. 5 and 6, the AE activity starts at a deformation level exceeding that which caused the damage during the past loading 36
Fig. 4. Applied load (actuator 1) and total energy for the 2% test. Fig. 5. Applied load at actuators 1 & 2 (background plot) and AE energy from flexible side column 1 (channels 1-8) and for column 2 (channels 9-16), respectively. (initial test at 0.30 g). Direct comparison between past and present loading, as a means to calculate Felicity effect, is not possible due to the different nature of applied loads as well as the addition of concrete jacket on columns 1 and 2. Moreover, it is worth noting that there is an absence of AE activity during a displacement hold at relative high force level between 5000- 5800 sec, implying no creep effects during that period. Finally, it is worth noting that the energy scale for columns 3 and 4 in Fig. 6 is one order of magnitude lower than that for columns 1 and 2 in Fig. 5. 37
Page 3 and 4: JOURNAL OF ACOUSTIC EMISSION VOLUME
Page 5 and 6: 25-194 ACOUSTIC EMISSION SOURCE LOC
Page 7 and 8: Volume 25 (2007) AUTHORS INDEX DIMI
Page 9 and 10: YUICHI TOMODA, 25-021 T. TOUTOUNTZA
Page 11 and 12: Notes for Contributors 1. General T
Page 13 and 14: In Memoriam H. Reginald Hardy, Jr.
Page 15 and 16: STRUCTURAL INTEGRITY EVALUATION USI
Page 17 and 18: The power-law AE behavior was recen
Page 19 and 20: sorting out the original signals, e
Page 21 and 22: Wood [36] in Australia has been usi
Page 23 and 24: One needs to appreciate the difficu
Page 25 and 26: In geotechnical applications, the p
Page 27 and 28: methods include the use of combined
Page 29 and 30: should take. Past attempts for stru
Page 31 and 32: 11. Suzuki, T., Ohtsu, M., Aoki, M.
Page 33 and 34: 40. http://en.wikipedia.org/wiki/Ma
Page 35 and 36: Abstract ACOUSTIC EMISSION TECHNIQU
Page 37 and 38: Fig. 1 Damage qualification by the
Page 39 and 40: After adding the data of a tested s
Page 41 and 42: Fig. 8 Sketch of a reinforced concr
Page 43 and 44: (3) Corrosion Process of Reinforced
Page 45 and 46: analysis. Corrosion cracking was si
Page 47 and 48: ACOUSTIC EMISSION MONITORING OF REI
Page 49: which - contrary to current beliefs
Page 53 and 54: concrete and the jacket. Visual ins
Page 55 and 56: Based on conventional analysis, AE
Page 57 and 58: 2. Experimental The model pipe syst
Page 59 and 60: pressure, respectively. This is ana
Page 61 and 62: Fig. 6: Power spectra from fast Fou
Page 63 and 64: small leaks (below 0.1 mm diameter)
Page 65 and 66: ACOUSTIC EMISSION TECHNIQUE APPLIED
Page 67 and 68: parameters in time domain and (c) m
Page 69 and 70: above the threshold level of 40 dB
Page 71 and 72: energy, i.e., high amplitude and lo
Page 73 and 74: An optical microscopy observation o
Page 75 and 76: Continuous WT (CWT) is defined as a
Page 77 and 78: Fig. 8. Typical AE waveforms, their
Page 79 and 80: followed by abrupt jumps in the det
Page 81 and 82: E. Landis (1999), “Micro-macro fr
Page 83 and 84: EVALUATION OF REPAIR EFFECT FOR DET
Page 85 and 86: Fig. 2 Sensor array for tomography
Page 87 and 88: 2 [ ] 2 k 3 9 2 2 1 f () 0 f ()
Page 89 and 90: At these depths, a complicated and
Page 91 and 92: The number of AE hits after repair
Page 93 and 94: damage indices of Calm and Load rat
Page 95 and 96: PVDF is a semicrystalline polymer,
Page 97 and 98: After these preliminary tests, the
Page 99 and 100: of PVDF sensors does not seem to ha
Page 101 and 102:
Fig. 10. Evolution of a typical PAD
Page 103 and 104:
Fig. 17. Evolution of a typical dur
Page 105 and 106:
I-G. Kim, H-Y. Lee and J-W. Kim (20
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Pencil-lead breaks are monopoles an
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Fig. 1 Displacement vs. time, sourc
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Fig. 5 Displacement vs. time, sourc
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Fig. 8 Displacement versus time for
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Fig. 10 Displacement vs. time. Sour
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Fig. 14 Signal amplitude versus tim
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To better relate these PLB and FEM
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HIGH-TEMPERATURE ACOUSTIC EMISSION
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thickness of 9 μm. The AlN element
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Fig. 5 Experimental setup for AE mo
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scales (and possibly salt cracks at
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DAMPING, NOISE, AND IN-PLANE RESPON
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The sharper resonance in Fig. 1c is
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i 2 RMS VDCC0 k BT = , g m 2 i
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ecause in-plane motion mostly produ
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4. B. Bahreyni, C. Shafai, Fabricat
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We first introduce our new quadridi
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Fig. 4 Amplitude profile as a funct
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Fig. 6 Change of room temperature (
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3) There are slight time lags in th
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Function Generator (FG) The functio
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Table 1 Results for continuous sens
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Fig. 7 pulse response XXX, filter :
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Fig. 11: Noise spectrum VS30-SIC-46
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waves propagate in a plate like str
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0.15 0 100kHz Driving pulse 10 100k
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0.45 0 100kHz Driving pulse 30 100k
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the sensor response to different fr
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CHARACTERISTICS OFACOUSTIC EMISSION
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Results and Discussion Shrinkage pr
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sapwood. Norway spruce wood consist
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most of the cells reached the fiber
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CHARACTERIZATION OF TITANIUM HYDRID
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Growth behavior of hydrides We stud
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were determined by the tensile test
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Figure 9 shows the Mode-I cracks in
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Results obtained are summarized as
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process of hydrogen destruction of
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Amplitude [dB] 60 55 50 45 40 35 30
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(Fig. 7) relative to the material a
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is shown in Table 1. Test specimens
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Fig. 4 Two types of AE signals dete
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the charging solution at 25 o C, by
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ANALYSIS OF ACOUSTIC EMISSION FROM
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nearly same waveforms for the first
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values). Most (11 of 14) of the rec
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Type-D (at 3.45 ms). In this sample
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NEURAL NETWORK BURST PRESSURE PREDI
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temperature, while the remaining se
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not properly set). This results in
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Conclusions Table 3 Summary of trai
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accurate source locations could be
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Fig. 1 Group velocities versus freq
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plane source orientation. But the l
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Fig. 9 Out-of-plane displacement vs
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Fig. 11 WTs of Fig. 8 with superimp
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Fig. 13 WTs of Fig. 10 with superim
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Table 3 At 102 kHz, WT peak arrival
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Fig. 17 Frequency of maximum WT int
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Fig. 18 Arrangement of sensors (#1,
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location calculation result that yi
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NOVEL ACOUSTIC EMISSION SOURCE LOCA
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tion resolution. It should be noted
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The specimen with numerous holes wa
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Fig. 5. Comparison of location meth
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Conclusions Delta-T source location
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Our approach This conceptual view c
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Voronoi Construction: Taking a case
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Fig. 6: Source location on a clamp
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PROBABILITY OF DETECTION FOR ACOUST
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POD is determined at the convergenc
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Fig. 2: Setup for illustrative runs
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Fig. 7: Probability of location (PO
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AE signals were filtered by high-pa
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Fig. 3 Accuracy and variations of a
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Fig. 7 Accuracy and variations of a
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eference data. The absolute values
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REAL-TIME DENOISING OF AE SIGNALS B
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600 500 400 300 200 kHz700 Frequenc
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the STFT result (Fig. 4(b)). Theref
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MONITORING THE EVOLUTION OF INDIVID
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the type of filtering, number of su
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was observed for either actuator. F
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Conclusions An experimental methodo
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the onset of pulses, consequently,
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zeros. The locations where a patter
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The reliability of the additional p
Page 281 and 282:
AE MONITORING OF SOIL CORROSION OF
Page 283 and 284:
Fig. 2 Cumulative AE counts with ap
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cumulative event counts and amplitu
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AE was monitored using three types
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Our conclusion from these tests is
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measurements with an Exxon Nuclear
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equipment manufacturer), CISE (AE t
Page 295 and 296:
Automatic testing of receptacles du
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The finalized standards are: • EN
Page 299 and 300:
14. Tscheliesnig P., Lackner G., He
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Fig. 1. Typical high-temperature cr
Page 303 and 304:
• Emission rates are much higher
Page 305 and 306:
Fig. 4. Results of AE monitoring of
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examination at 2000-5000X was able
Page 309 and 310:
samples extracted from the beam aft
Page 311 and 312:
The relative comparison of the size
Page 313 and 314:
Fig. 3. Schema of VB Application fo
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Fig. 5. Microstructural observation
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Fig. 7 AE source locations for diff
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Fig. 9 CT images and corresponding
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A.M. Brandt, G. Prokopski, J. Mater
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conducted with AE technique. The AE
Page 325 and 326:
After location of the events, inter
Page 327 and 328:
The transit times of the individual
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6) B. Schechinger, T. Vogel, Acoust
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greater than the available anchorag
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location uncertainty and is the roo
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Figures 4 and 5 illustrate all loca
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ig cracks form, localization of AE
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ased on magnetic induction, while i
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Fig. 3. AE sensors positioning on b
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As a further evaluation of the degr
Page 345 and 346:
EARLY FAULT DETECTION AT GEAR UNITS
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Acoustic Emission Analysis at Rotat
Page 349 and 350:
The fixed bearing at the beginning
Page 351 and 352:
The time-frequency components of a
Page 353 and 354:
Additionally, the gear test bench h
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APPLICATION OF ACOUSTIC EMISSION IN
Page 357 and 358:
Measurements of the acoustic backgr
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Fig. 6. RMS for different ranges of
Page 361 and 362:
which indicate the transition from
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surface condition. It has already b
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( 2 1) 2) ! kx1 ! k c ! x + c ! k (
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Fig. 6: Signal above normal and def
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DAMAGE ASSESSMENT OF GEARBOX OPERAT
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The waveform streaming can be trigg
Page 373 and 374:
Extracting features using different
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The classifier was used to identify
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ASL spectral energy is further calc
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2 #_ of _ Sensors 2 2 2 ( x ) (
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Simulated Failure Plane One hundred
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It has been documented that the ini
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(a) (b) (c) (d) 95% _ 98% 98% _ 100
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IMPACT IMAGING METHOD TO MAP DAMAGE
Page 389 and 390:
e) Step d) was repeated until the a
Page 391 and 392:
Panel A Panel B Panel C Panel D Fig
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Journal of AE, Volume 25, 2007 (ca. 26 MB) - AEWG

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