Structural vibration measurement with multiple synchronous cameras

2021 ◽  
Vol 157 ◽  
pp. 107742
Author(s):  
Roberto Del Sal ◽  
Loris Dal Bo ◽  
Emanuele Turco ◽  
Andrea Fusiello ◽  
Alessandro Zanarini ◽  
...  
Keyword(s):  
Vibration Measurement ◽  
Structural Vibration

Utilizing an Arduino-Based Accelerometer in Civil Engineering Applications in Undergraduate Education

2021 ◽  
Author(s):  
Ahu Komec Mutlu ◽  
Ulgen Mert Tugsal ◽  
Ahmet Anil Dindar
Keyword(s):  
Engineering Education ◽  
Undergraduate Education ◽  
Microelectromechanical Systems ◽  
Civil Engineering ◽  
Vibration Measurement ◽  
Structural Vibration ◽  
Response Analysis ◽  
Seismic Safety ◽  
Vibration Data ◽  
Python Programming

Abstract One of the most important issues in civil engineering undergraduate education is response analysis of structures for earthquake-resistant design. Precautions that should be taken against seismic hazards not only include the design of earthquake-safe buildings but also monitoring the strength and dynamic characteristics of structures. Because this is an important topic in theoretical aspects of civil engineering education at the undergraduate level, it is essential to have opportunities to perform practices so students can better understand lectures. In the Gebze Technical University (GTU) Civil Engineering Department, we guide our undergraduate students to graduate as competent engineers who use practice tools. For this purpose, we designed an Arduino-based accelerometer device and its software toolkit, which records and visualizes structural vibration data in the process of learning the best practices of seismic safety. The device contains Arduino UNO board ADXL345 MEMS (microelectromechanical systems) Accelerometer and microSD card module. Both Arduino and Python open-source programming languages were implemented in the device. We have produced a total number of 15 accelerometers (named the ACCE_edu-Arduino based accelerometer for Civil Engineering education) integrating these cards and sensors that are widely used for vibration measurement and interpretation to record vibration data. Within the scope of “Python programming” lectures in the GTU undergraduate program, these toolkits will be used to obtain data that would be recorded, stored, visualized, and filtered using Python programming language, which provides a practical application in data processing.

Engineering Analysis on Vibration Characteristics of Merchant Vessels with Theoretical and Onboard Test Approaches

2001 ◽  
Vol 38 (04) ◽  
pp. 241-249
Author(s):  
Tong-Ming Wu
Keyword(s):  
Finite Element ◽  
Empirical Formula ◽  
Ship Design ◽  
Vibration Characteristics ◽  
System Stability ◽  
Vibration Measurement ◽  
Structural Vibration ◽  
Design Stage ◽  
Primary Concern ◽  
Vibration Behavior

Recent development of ship design, such as flexible hull structures with somewhat light ship weight in terms of larger/longer/wider principal particulars and long-stroke diesel engine of high brake horsepower, has been demonstrated dramatically. Nevertheless, this kind of ship design concept harmfully degrades system stability of electronic instrumentation and operating performance of human beings in sea service. Therefore practical prediction on structural vibration behavior of designed vessels is of primary concern and has to be taken into account at the preliminary design stage. Two theoretical approaches, preliminary prediction by empirical formula and numerical solutions by finite-element technique (matrix analysis methodology), are briefly reviewed. An onboard test system for structural vibration measurement is developed and comprehensively described. In fact, a standard procedure of data acquisition and analysis system for structural vibration measurement is already set up to deal with several kinds of vibration research work in practical engineering fields. Natural frequencies of vibration behavior for a 1200 TEU container vessel are checked out by preliminary prediction of empirical formula and measurement data from onboard tests. Moreover, a comparison study by finite-element analysis and full-scale measurement is also performed on vibration characteristics of hull structures. The amplitude of vibration acceleration induced by unbalanced moment of the main engine is calculated for any point of hull at the resonance condition and the installation of an electrical balancer onboard is taken into account for vibration countermeasures also. All approximate predictions, compared with onboard test results, are found to meet with an acceptable level of engineering accuracy. The practical package of approximate approaches in both theoretical and onboard test aspects to investigate vibration characteristics of structures, for instance, hull, machinery, piping, and shafting system, in universal service is quite reliable and easily performed on portable computers for extensive engineering applications.

scholarly journals SMART SENSOR MIDDLEWARE DEVELOPMENT FOR DENSE STRUCTURAL VIBRATION MEASUREMENT

2009 ◽  
Vol 65 (2) ◽  
pp. 523-535 ◽  
Author(s):  
Tomonori NAGAYAMA ◽  
B. F. SPENCER Jr. ◽  
Yozo FUJINO
Keyword(s):  
Vibration Measurement ◽  
Structural Vibration ◽  
Smart Sensor

scholarly journals Optical Scanning for Structural Vibration Measurement

2011 ◽  
Vol 22 (2) ◽  
pp. 61-75 ◽  
Author(s):  
Belen Ferrer ◽  
Julian Espinosa ◽  
Jorge Perez ◽  
Salvador Ivorra ◽  
David Mas
Keyword(s):  
Vibration Measurement ◽  
Structural Vibration ◽  
Optical Scanning

Case Studies of LDV-Aided Dynamic Testing

2012 ◽  
Vol 226-228 ◽  
pp. 2066-2071 ◽  
Author(s):  
Kao Shan Dai ◽  
Xiao Song Ren ◽  
Qing Jun Chen ◽  
Bin Zhao
Keyword(s):  
Prestressed Concrete ◽  
Dynamic Testing ◽  
Laser Doppler Vibrometer ◽  
Laser Doppler ◽  
Vibration Measurement ◽  
Structural Vibration ◽  
Structural Dynamic ◽  
Vibration Sensors ◽  
Sensing Technology ◽  
Contact Sensing

The laser Doppler vibrometer is a non-contact sensing technique developed based on the Doppler effect of a laser beam emerging from a subject surface. As a vibration transducer, the laser Doppler vibrometer offers many advantages over the conventional contact vibration sensors. It allows remote, non-intrusive measurement of structural vibration and it is very useful in scenarios when traditional contacting measurement is inconvenient. In this paper, four laser-based structural dynamic studies were presented and some results were briefly reported, which include laboratory dynamic testing of a bolted steel beam, a scaled-down high-rise building model, and a prestressed concrete reaction wall, and field vibration measurement of a viaduct bridge. Through these demonstrating cases, it is anticipated to help civil engineers get familiar with the laser-based sensing technology and to extend their selections for effective measurement approaches during experimental research.

Establishing Platform Foundation Capacity Using Topside Vibration Measurements

2010 ◽  
Author(s):  
Jared L. Black
Keyword(s):  
Structural Analysis ◽  
Resonance Condition ◽  
Steel Structure ◽  
Field Work ◽  
Vibration Monitoring ◽  
Vibration Measurement ◽  
Structural Vibration ◽  
Lateral Stiffness ◽  
Resonant Frequencies ◽  
Monitoring Procedure

This paper describes how a structural vibration monitoring procedure was used in combination with structural analysis modeling to determine the foundation capacity of an existing offshore platform. The project was initiated due to concern that the foundation capacity was marginal for a needed expansion of the topsides process system. The field work consisted of conducting a sequence of vibration measurement for a range of increasing deck loads. Since the platform’s resonant frequencies depend on the structural stiffness and mass, each deck loading (mass) produced a slightly different resonance condition. The set of resonant frequencies obtained for the different deck loads allows one to deduce the stiffness of the structure-foundation system. The stiffness of the steel structure (jacket and deck) was established with structural analysis. The remaining unknown is the axial and lateral stiffness of the pile foundation. Using the torsional resonant frequencies, the lateral stiffness of the pile array and individual piles was established. Then using the translational resonance, the axial pile stiffness was found. Based on these analyses, the platform’s foundation capacity was estimated to be significantly greater than that predicted by the standard pile capacity design recipe. The structure was deemed adequate for the planned topside modification.

Vibration Measurement Using Additive Speckle Interferometry

1995 ◽  
Author(s):  
Liusheng Wang ◽  
Pavel Fomitchov ◽  
Sridhar Krishnaswamy
Keyword(s):  
Reference Beam ◽  
Vibration Measurement ◽  
Structural Vibration ◽  
Calculation Algorithm ◽  
Sinusoidal Vibration ◽  
Flat Bottom ◽  
Phase Calculation ◽  
Speckle Patterns ◽  
Phase Map ◽  
Fringe Patterns

Abstract A method for obtaining structural vibration amplitudes quantitatively is proposed based on the stroboscopic speckle interferometer. The technique requires five frames of additive speckle patterns: the first one (S0) taken with the laser illumination pulsed at instants when the vibration achieves its two zero amplitude positions within one sinusoidal vibration cycle of the specimen; and the remaining four (S1 through S4) taken with the illumination pulses arranged at times when the vibration is at its maximum and minimum amplitudes. During the acquisition of speckle patterns S1 through S4, the phase of the reference beam is appropriately shifted between the two pulses within each vibration cycle. The last four speckle patterns are then subtracted from the first one to yield four correlation fringe patterns with relative phase shifts of 0, π/2, π and 3π/2 respectively. These fringe patterns are then utilized to derive a phase map using a four-step phase calculation algorithm and finally the vibration amplitude and the sign of the vibrational nodes can be readily obtained from the phase map quantitatively. Results have been obtained using a speckle shearographic setup for the vibration measurement of a flat bottom-holed aluminum specimen vibrating at different frequencies.

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