Construction of a three–dimensional, large–scale shaking table and development of core technology

Author(s):  
Nobuyuki Ogawa ◽  
Keiichi Ohtani ◽  
Tsuneo Katayama ◽  
Heki Shibata
2013 ◽  
Vol 650 ◽  
pp. 518-522
Author(s):  
Juan Xiao

Main characteristics of recent human motion capture systems are analyzed in the paper firstly. Based on that, a new multi-user aerobics wireless human motion capture system based on MEMS is proposed. Design of its framework and core technology solutions including large-scale data obtain, multi-hop wireless sensor and high-frequency real-time transmission are put forward. Finally, three-dimensional real-time reconstructions of the multi-user aerobics wireless motion capture system are showed in the paper.


2018 ◽  
Vol 14 (9) ◽  
pp. 155014771880062
Author(s):  
Baohua Shan ◽  
Wenting Yuan ◽  
Hai Wang ◽  
Zhanxuan Zuo

In lab or actual engineering, the traditional contact sensors are always destroyed with damage of structures or models, and this leads to the failure of entire dynamic measurement. To deal with this issue, this article proposes a three-dimensional displacement measurement approach based on the parallel stereovision model. This approach combines the efficient large-scale stereo matching algorithm and the digital image correlation approach to obtain three-dimensional displacement of structural vibration response. In this article, the digital image correlation method is employed to match sequential images of left and right cameras, and the efficient large-scale stereo algorithm is used to obtain the disparity between the left and right images at each moment. Based on the parallel stereovision model, the three-dimensional coordinates of the measured point on the structural surface are achieved accordingly. A shaking table test of a three-story frame model under El Centro earthquake is performed in lab. Experimental results indicate that the displacement curves acquired by the linear variable differential transformers and the proposed method agree well, and this testifies the reliability and effectiveness of the presented approach. Only the presented stereovision approach attains the entire displacement curves of structural collapse when the model collapses, and this demonstrates the capability of the presented stereovision approach monitoring structural collapse.


1995 ◽  
Vol 117 (3) ◽  
pp. 245-249 ◽  
Author(s):  
K. Suzuki ◽  
T. Watanabe ◽  
T. Mitsumori ◽  
N. Shimizu ◽  
H. Kobayashi ◽  
...  

This report deals with the experimental study of seismic response behavior of piping systems in industrial facilities such as petrochemical, oil refinery, and nuclear plants. Special attention is focused on the nonlinear dynamic response of piping systems due to frictional vibration appearing in piping and supporting devices. A three-dimensional mock-up piping and supporting structure model wherein piping is of 30-m length and 200-mm diameter is excited by a large-scale (15 m × 15 m) shaking table belonging to the National Research Institute for Earth Science and Disaster Prevention in Tsukuba, Ibaraki. Power spectra of the response vibration and the loading-response relationship in the form of a hysteresis loop under several loading conditions are obtained. The response reduction effect caused by frictional vibration is evaluated and demonstrated in terms of “response reduction factor.”


2012 ◽  
Vol 204-208 ◽  
pp. 2600-2604
Author(s):  
Ying Ming Zhou ◽  
Shu Wei Wang ◽  
Peng Wang ◽  
Li Na Yao

In this paper, the subway station structure seismic response of large-scale three-dimensional shaking table model test is analysis, the model system acceleration response time, the stress response of the model structure of the schedule and structure of the surface of the earth pressure time is obtained, which has been the subway underground structure seismic response of the general law, the conclusion can provide a reliable basis and guidance for the seismic design of the MTR underground structures in the general venue.


2018 ◽  
Vol 10 (12) ◽  
pp. 1902 ◽  
Author(s):  
Xiaohua Tong ◽  
Kuifeng Luan ◽  
Xianglei Liu ◽  
Shijie Liu ◽  
Peng Chen ◽  
...  

Laminated rubber bearings are widely used for the mitigation of seismic damage of large-scale structures and equipment. However, owing to the flexibility in horizontal direction, the traditional contacted transducer is difficult to acquire the displacement data accurately in the three directions, respectively. In this paper, three-dimensional displacement measurement of laminated rubber bearing based on the large-scale shaking table is achieved by the use of a tri-camera high-speed videogrammetric system consisting of three complementary-metal-oxide-semiconductor (CMOS) cameras, one synchronous controller, and one pair of 1000 watt light sources, which are used to simultaneously acquire the tri-camera image sequences of laminated rubber bearing at a speed of 300 frames per second (fps). Firstly, this paper proposes a fast image block technique for detecting and tracking targets in tri-camera image sequences by integration of techniques morphological edge detection, attribute based ellipse extraction and least-squares-based fitting adjustment. Secondly, this paper presents an integrated bundle adjustment approach, which brings continuous tracking points into one collinearity condition equation, to reconstruct the three dimensional coordinates of continuous tracking points, for the purpose of improving the accuracy of three-dimensional coordinates of tracking points based on tri-camera image sequences. At last, an empirical experiment was conducted to measure the three-dimensional displacement of laminated rubber bearings on the shaking table by the use of the proposed method. The experimental results showed that the proposed method could obtain three-dimensional displacement of laminated rubber bearings with an accuracy of more than 0.5 mm.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1940
Author(s):  
Muhammad Usman Naseer ◽  
Ants Kallaste ◽  
Bilal Asad ◽  
Toomas Vaimann ◽  
Anton Rassõlkin

This paper presents current research trends and prospects of utilizing additive manufacturing (AM) techniques to manufacture electrical machines. Modern-day machine applications require extraordinary performance parameters such as high power-density, integrated functionalities, improved thermal, mechanical & electromagnetic properties. AM offers a higher degree of design flexibility to achieve these performance parameters, which is impossible to realize through conventional manufacturing techniques. AM has a lot to offer in every aspect of machine fabrication, such that from size/weight reduction to the realization of complex geometric designs. However, some practical limitations of existing AM techniques restrict their utilization in large scale production industry. The introduction of three-dimensional asymmetry in machine design is an aspect that can be exploited most with the prevalent level of research in AM. In order to take one step further towards the enablement of large-scale production of AM-built electrical machines, this paper also discusses some machine types which can best utilize existing developments in the field of AM.


2021 ◽  
Vol 104 (1) ◽  
pp. 003685042098705
Author(s):  
Xinran Wang ◽  
Yangli Zhu ◽  
Wen Li ◽  
Dongxu Hu ◽  
Xuehui Zhang ◽  
...  

This paper focuses on the effects of the off-design operation of CAES on the dynamic characteristics of the triple-gear-rotor system. A finite element model of the system is set up with unbalanced excitations, torque load excitations, and backlash which lead to variations of tooth contact status. An experiment is carried out to verify the accuracy of the mathematical model. The results show that when the system is subjected to large-scale torque load lifting at a high rotating speed, it has two stages of relatively strong periodicity when the torque load is light, and of chaotic when the torque load is heavy, with the transition between the two states being relatively quick and violent. The analysis of the three-dimensional acceleration spectrum and the meshing force shows that the variation in the meshing state and the fluctuation of the meshing force is the basic reasons for the variation in the system response with the torque load. In addition, the three rotors in the triple-gear-rotor system studied show a strong similarity in the meshing states and meshing force fluctuations, which result in the similarity in the dynamic responses of the three rotors.


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