How to improve the seismic capacity of the building? Servo electric cylinder to contribute!
Release time:
2023-08-14 10:11
Source:
Recently, there have been frequent natural disasters. A few days ago, earthquakes broke out in Shandong and Sichuan in the early morning, which attracted the hearts of the whole country. At the same time, many partners began to pay attention to the earthquake resistance of the house they lived in. When the earthquake comes, should they run or hide on the spot?
Xiao Ao came to talk with you about one of the most important means in structural seismic test research, and it is also the place where servo electric cylinders can make great efforts in the future-earthquake simulation shaking table.
The basic principle of seismic simulation shaking table is to place the test object on the shaking table with sufficient rigidity, and make the table of the shaking table reproduce the input seismic waveform through the excitation system, so that the test object is in a simulated seismic environment, so as to test its performance under the action of the earthquake, and then visually show the failure mechanism and dynamic characteristics of the building structure when vibrating, which can test the seismic performance of the specimen, the effectiveness of seismic measures can also be tested.
To put it simply, the building is placed on a shaking table, and then the shaking table starts to vibrate wildly according to the vibration waves recorded in the past into motion modes, thus obtaining the damage of the building under different earthquake magnitudes.
* Japanese E-Defense shaking table model test
The seismic simulation shaking table system is a complex device, mainly composed of shaking table, hydraulic/electric cylinder drive and power system, test and analysis system, and control system. The following figure:
* Schematic diagram of seismic simulation shaking table system
among them,
1) The servo control system is the basis for realizing the control function of the seismic simulation shaking table. Its main function is to receive the servo drive signal given by the vibration system, output servo control instructions, and control the movement of the exciter system to control the movement of the console. In order to ensure the accuracy of the simulated shock wave, new control techniques such as robust control, minimum control synthesis, adaptive inverse control, adaptive harmonic suppression, and amplitude-phase control are all applied to the vibration control of the shaking table.
2) In the actual application process, electro-hydraulic excitation has high precision and large gravity, but it also has disadvantages such as high price, oil leakage and difficult maintenance, and the main domestic hydraulic control system still relies on imports, so some researchers propose to use servo electric cylinder to replace the original electro-hydraulic excitation. The following figure:
Its working principle is as follows: the seismic waveform is input to the computer controller, the computer controller takes the waveform as the control target, gives instructions to the servo driver, drives the servo motor to rotate, makes the vibrating table vibrate along the one-dimensional direction through the mechanical transmission mechanism, the acceleration sensor collects the acceleration signal of the table and the driver sends a signal to feed back to the controller, and the controller compares the signal with the input waveform after receiving the signal.
Because the servo electric cylinder structure is simplified, the cost is reduced, the production and test cycle is shortened, the performance of the vibration table is also improving, so the small engineering structure test and the university test teaching use of the scene, the servo electric cylinder type seismic simulation vibration table is more and more popular.
The above seismic simulation shaking table is mainly used in the seismic test of large-scale projects such as construction projects, water conservancy projects and nuclear power projects.
In fact, in life, we can also see that there have been some earthquake simulation huts on the market, which also use servo electric cylinders as vibrators. Viewers can stand on the shaking table and experience how to quickly stabilize their bodies and find hiding places under the magnitude of 3 to 8.
With the accuracy of servo electric bars getting higher and higher and the control technology getting more and more advanced, it is believed that the future earthquake simulation shaking table will more truly present various dynamics before, during and after the earthquake, which can greatly promote the construction, water conservancy and other projects to improve the structural earthquake prevention level, and also help people to intuitively learn more scientific and agile escape skills to deal with sudden earthquakes through exercises in it.
References:
[1] Gu Haodi. Research on Foundation Design of Earthquake Simulation Shaking Table [D] Hebei: Shijiazhuang Tiedao University, 2022
[2] Mu Yuanbo. Research on motion control method of instrument calibration platform based on LabVIEW [D] Institute of Seismology, China Earthquake Administration, 2020
[3] Kong Jie. Research on key technology of seismic simulation shaking table control [D] Zhejiang: Zhejiang University, 2019
[4] Cao Jun, Yang Junjie, Ying Yi Seconds, Zhang Xuefeng. Application of AC Servo Electric Cylinder in Earthquake Simulation Shaking Table [J]. Test Technology and Management, 2011 (4):67-70
[5] Zhejiang University of Technology, Hangzhou Bangwei Electromechanical Control Engineering Co., Ltd. Small engineering structure electric servo cylinder seismic simulation shaking table: 201310504622.3.2014.01.22
[6] Zhejiang University of Technology, Hangzhou Bangwei Electromechanical Control Engineering Co., Ltd. An electric servo bar seismic simulation shaking table control system: 201810786119.4.2018.12.11
Earthquake, shaking table, servo, control, electric, vibration, servo electric cylinder
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