Study on Performance Evaluation of MEMS Sensors and Data Integration Methods for Expected Use to Determine Damage Degrees of Existing Structures

2017 ◽  
Vol 12 (5) ◽  
pp. 858-867 ◽  
Author(s):  
Tomohiro Sasaki ◽  
◽  
Koichi Kajiwara ◽  
Takuzo Yamashita ◽  
Takuya Toyoshi

The shake table test of small-scaled steel frame structure was conducted using large-scale earthquake simulator at the National Research Institute for Earth Science and Disaster Resilience (NIED) in Tsukuba, Ibaragi. This paper presents the performance evaluation of Micro Electro Mechanical Systems (MEMS) type accelerometers, which are recently being used in various fields, comparing with the conventional servo type accelerometers. In addition, this paper discussed the integration method of the measured acceleration into displacements, which is suitable for structural damage evaluation due to strong earthquakes.

Author(s):  
Shojiro Oka ◽  
Kouichi Kajiwara ◽  
Tomohiro Itoh

After the 1995 Kobe earthquake in Japan, National Research Institute for Earth Science and Disaster Prevention started to construct a large-scale 3-D shaking table, called “E-Defense”. The facility is to be completed in 2005, and failure experiments of many kinds of structures are to be performed. As for a feasibility study of those experiments, a plan of a full-scale tank failure test was investigated. A steel cylindrical tank of 990m3 capacity was selected as a typical liquid storage tank. The height is about 15m and the diameter is about 10m. The total mass, with full of water, is about 1 MN (1,000 tonf). The tank is constructed on a steel frame structure for specimen handling and test facility protection, and set on the shaking table. To prevent facility failure due to a mass of water leakage, waterproof walls are necessary at the lower part of the frame. Ground motion recorded at the Kobe earthquake is applied to the shaking table, and elephant foot bulge buckling is expected to occur at the bottom portion of the tank. Through this preliminary planning, technical feasibility of tank failure tests was confirmed, and problems to be solved for actual planning were clarified.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Nicola Caterino ◽  
Mariacristina Spizzuoco ◽  
Julian M. Londoño ◽  
Antonio Occhiuzzi

This work focuses on the issues to deal with when approaching experimental testing of structures equipped with semiactive control (SA) systems. It starts from practical experience authors gained in a recent wide campaign on a large scale steel frame structure provided with a control system based on magnetorheological dampers. The latter are special devices able to achieve a wide range of physical behaviours using low-power electrical currents. Experimental activities involving the use of controllable devices require special attention in solving specific aspects that characterize each of the three phases of the SA control loop: acquisition, processing, and command. Most of them are uncommon to any other type of structural testing. This paper emphasizes the importance of the experimental assessment of SA systems and shows how many problematic issues likely to happen in real applications are also present when testing these systems experimentally. This paper highlights several problematic aspects and illustrates how they can be addressed in order to achieve a more realistic evaluation of the effectiveness of SA control solutions. Undesired and unavoidable effects like delays and control malfunction are also remarked. A discussion on the way to reduce their incidence is also offered.


2010 ◽  
Vol 163-167 ◽  
pp. 2693-2698 ◽  
Author(s):  
Peng Sun ◽  
Ai Qun Li ◽  
You Liang Ding ◽  
Yang Deng

The damage alarming analysis based on wavelet packet energy spectrum is performed with regard to the experimental data of Benchmark steel frame structure and online monitoring data of Runyang Suspension Bridge, on the basis of which the damage alarming effects using various wavelet functions are investigated in detail. Results reveal that the Daubechies wavelet functions and Coiflets wavelet functions are applicable to structural damage alarming.


2012 ◽  
Vol 226-228 ◽  
pp. 1214-1217
Author(s):  
Yan Sheng Song ◽  
Zong Guang Sun ◽  
Li Ye Sun

Based on the statistical probability of abnormal frequency offset, this paper puts forward a new structural damage alarm index. Demonstrating the feasibility of corresponding structural damage alarming method, this article introduces the index to analize a steel frame structure in frequency domain. The results show the abnormal index defined in sense of statistics indicates the abnormity of corresponding test cases clearly.


1990 ◽  
Vol 6 (2) ◽  
pp. 403-417 ◽  
Author(s):  
Michael C. Griffith ◽  
Ian D. Aiken ◽  
James M. Kelly

Earthquake simulator tests were performed on a 1/5-scale, 6-story reinforced concrete shear-wall structure and a 1/4-scale, 9-story braced steel frame structure. The structures were supported by five different base isolation systems which consisted of various types and combinations of elastomeric bearings. The main objective of this study was to compare the peak experimental displacements of the base isolation systems tested with values given by the tentative base isolation design provisions proposed by the Seismology Committee of the Structural Engineers Association of Northern California (SEAONC). Comparisons of experimental results and values from the SEAONC base isolation design formula for displacements indicated that the formula is generally conservative, even for predominantly low frequency earthquake motions, provided the ground motion coefficient Av (based on the effective peak velocity as defined by ATC 3-06) is used in the design equation for base-isolated structures with periods greater than 1 second.


2014 ◽  
Vol 578-579 ◽  
pp. 1153-1156
Author(s):  
Hong Biao Liu ◽  
Qiang Zhang

In order to verify the feasibility and validity of frequency ratio as diagnostic parameter in structural damage detection proposed in the Musical Tone Law Method (MTLM), steel pipes and three-story steel frame structure model tests are carried out. According to the experiment results, it is clear that the diagnostic parameter is effective for symmetrical structure in structural damage detection, such as cable structure, framed structure, and so on. Model tests prove that the frequency ratio is effective in detecting the 3mm width crack damage of steel pipe. In the damage detection test of three-story steel frame structure, the parameter also successfully diagnosed the damage caused by bolts loosening at the node of model.


2020 ◽  
Vol 14 (1) ◽  
pp. 69-81
Author(s):  
C.H. Li ◽  
Q.W. Yang

Background: Structural damage identification is a very important subject in the field of civil, mechanical and aerospace engineering according to recent patents. Optimal sensor placement is one of the key problems to be solved in structural damage identification. Methods: This paper presents a simple and convenient algorithm for optimizing sensor locations for structural damage identification. Unlike other algorithms found in the published papers, the optimization procedure of sensor placement is divided into two stages. The first stage is to determine the key parts in the whole structure by their contribution to the global flexibility perturbation. The second stage is to place sensors on the nodes associated with those key parts for monitoring possible damage more efficiently. With the sensor locations determined by the proposed optimization process, structural damage can be readily identified by using the incomplete modes yielded from these optimized sensor measurements. In addition, an Improved Ridge Estimate (IRE) technique is proposed in this study to effectively resist the data errors due to modal truncation and measurement noise. Two truss structures and a frame structure are used as examples to demonstrate the feasibility and efficiency of the presented algorithm. Results: From the numerical results, structural damages can be successfully detected by the proposed method using the partial modes yielded by the optimal measurement with 5% noise level. Conclusion: It has been shown that the proposed method is simple to implement and effective for structural damage identification.


2012 ◽  
Vol 193-194 ◽  
pp. 1405-1413 ◽  
Author(s):  
Zhu Ling Yan ◽  
Bao Long Cui ◽  
Ke Zhang

This paper conducts analysis on beam-column extended end-plate semi-rigid connection joint concerning monotonic loading and cyclic loading of finite element through ANSYS program, mainly discussed the influence of parameters such as the form of end plate stiffening rib on anti-seismic performance of joint.


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