scholarly journals Analysis on Vibration Characteristics and Suppression Strategy of Vehicle Mounted GPR Detection Device for Tunnel Lining

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 309
Author(s):  
Yang Lei ◽  
Yong Zou ◽  
Tian Tian ◽  
Falin Qi ◽  
Bo Jiang
Keyword(s):  
High Speed ◽  
Control Program ◽  
Vibration Characteristics ◽  
Tunnel Lining ◽  
Railway Tunnel ◽  
Tunnel Detection ◽  
Adaptive Adjustment ◽  
And Control ◽  
Suppression Strategy

The GPR antenna is installed on the high-speed railway tunnel detection vehicle through the detection device to carry out non-contact nondestructive and rapid detection of the lining condition. Through simulation calculation and field vibration test data analysis, the vibration characteristics of the detection device are obtained. Vibration excitation is applied to GPR antennas to explore the amplitude-frequency sensitivity of echo signal affected by vibration when GPR detects tunnel lining, thus as to provide a basis for mechanism design and vibration control strategy. Through the optimization of the material properties, structural design, and control program of the detection device, the vibration frequency and amplitude of the detection device are optimized, the adaptive adjustment stability of the control system is improved, and the quality of GPR detection data is enhanced.

scholarly journals Novel Liquid Transfer Active Balancing System for Hollow Rotors of High-Speed Rotating Machinery

2019 ◽  
Vol 9 (5) ◽  
pp. 833 ◽  
Author(s):  
Xin Pan ◽  
Zhen Xie ◽  
Juan Lu ◽  
Haiqi Wu ◽  
Jinji Gao ◽  
...  
Keyword(s):  
High Speed ◽  
Control Program ◽  
Extraction Methods ◽  
Rotating Machinery ◽  
Rotor System ◽  
Maximum Speed ◽  
Monitoring And Control ◽  
Active Balancing ◽  
Liquid Transfer ◽  
And Control

With the development of high-speed rotating machinery, the unbalance vibration feature of each rotor system has a greater influence on the work efficiency, bearing life, operational time, etc. Therefore, an active balancing system is necessary to automatically reduce the unbalance vibration in the process of rotor operation. This study introduced a novel liquid transfer active balancing system for the hollow rotors, and compensation mass was performed by balance liquid transmission between two pairs of contra-positioned chambers. The performance of this new balance actuator was analyzed, including balancing velocity, balancing accuracy, and the effect on rotor dynamics. A monitoring and control program was constructed to control the balance actuator. Two extraction methods of synchronic vibration were introduced and quantitatively compared through simulation. A control program was developed and the control accuracy was within 1 ms. Furthermore, the effectiveness of the new balancing system was verified through active balance experiments and the maximum speed was 15,600 rpm. The results indicate that the balancing system could effectively decrease the unbalance vibration of the rotor system within 10 s, and the amount of decrease was more than 80%.

scholarly journals COLLABORATIVE TRIAL AND QUALITY CONTROL IN CHEMICAL ANALYSIS

2010 ◽  
Vol 2 (3) ◽  
pp. 135-141
Author(s):  
Narsito Narsito
Keyword(s):  
Quality Control ◽  
Chemical Analysis ◽  
Analytical Method ◽  
Control Charts ◽  
Analytical Data ◽  
Control Program ◽  
Quality Parameter ◽  
Quality Control Program ◽  
And Control

Abstract                                                             This paper deals with some practical problems related to the quality of analytical chemical data usually met in practice. Special attention is given to the topic of quality control in analytical chemistry, since analytical data is one of the primary information from which some important scientifically based decision are to be made. The present paper starts with brief description on some fundamental aspects associated with quality of analytical data, such as sources of variation of analytical data, criteria for quality of analytical method, quality assurance in chemical analysis. The assessment of quality parameter for analytical method like the use of standard materials as well as standard methods is given. Concerning with the quality control of analytical data, the use of several techniques, such as control samples and control charts, in monitoring analytical data in quality control program are described qualitatively.  In the final part of this paper, some important remarks for the preparation of collaborative trials, including the evaluation of accuracy and reproducibility of analytical method are also given Keywords: collaborative trials, quality control, analytical data Abstract                                                             This paper deals with some practical problems related to the quality of analytical chemical data usually met in practice. Special attention is given to the topic of quality control in analytical chemistry, since analytical data is one of the primary information from which some important scientifically based decision are to be made. The present paper starts with brief description on some fundamental aspects associated with quality of analytical data, such as sources of variation of analytical data, criteria for quality of analytical method, quality assurance in chemical analysis. The assessment of quality parameter for analytical method like the use of standard materials as well as standard methods is given. Concerning with the quality control of analytical data, the use of several techniques, such as control samples and control charts, in monitoring analytical data in quality control program are described qualitatively.  In the final part of this paper, some important remarks for the preparation of collaborative trials, including the evaluation of accuracy and reproducibility of analytical method are also given Keywords: collaborative trials, quality control, analytical data

Numerical Simulation on Mesoscopic Damage Evolution Mechanism of High-Speed Railway Tunnel Lining Concrete

2011 ◽  
Vol 90-93 ◽  
pp. 2248-2253
Author(s):  
Yun Dong Ma ◽  
Bo Li ◽  
Bin Fan
Keyword(s):  
High Speed ◽  
Damage Mechanism ◽  
Tunnel Lining ◽  
Concrete Lining ◽  
Railway Tunnel ◽  
High Speed Railway ◽  
Main Research ◽  
Elastic Module ◽  
Fatigue Loads ◽  
Research Stage

For the high-speed railway tunnel concrete lining, there have been some such initial damages as initial pores or cracks, therefore the initial damages will be expanded gradually under aerodynamic fatigue loads resulting from the high-speed train passing by tunnel, elastic module attenuation laws of concrete was adopted to reflect the effects of fatigue loads on the tunnel lining mesoscopic concrete, taking the second stage of the elastic module attenuation as the main research stage, the mesoscopic damage mechanism and fatigue damage cracks developing-and-changing laws of high-speed railway lining concrete were simulated under the repetitive aerodynamic loads. Study indicates: for the concrete lining with initial damages, under the repeated aerodynamic fatigue loads, the mechanical properties of the tunnel lining concrete will gradually deteriorate to the whole damage of the concrete structure, which will cause serious inference on the durability of the tunnel especially during the middle and later periods of the high-speed railway tunnel serving.

scholarly journals Experimental Investigation of Load-Bearing Mechanism of Underwater Mined-Tunnel Lining

2021 ◽  
Vol 9 (6) ◽  
pp. 627
Author(s):  
Zhiqiang Zhang ◽  
Binke Chen ◽  
Qingnan Lan
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Water Pressure ◽  
Tunnel Lining ◽  
Scale Model ◽  
Soil Pressure ◽  
Railway Tunnel ◽  
Load Bearing ◽  
Water Head ◽  
Design Speed

A series of model tests were performed to investigate the load-bearing mechanism of a mined railway tunnel lining under water pressure. To investigate the load-bearing characteristics of different types of linings, a fully closed water pressure exerting device for a noncircular section tunnel was invented. A large-scale model test (1:30) under combined water and soil pressures was conducted to investigate the mechanical characteristics, deformation, stress distribution, crack development process, and failure mode of the underwater mined-tunnel lining. The test results indicated that for the high-speed railway tunnel of Class IV surrounding rock with a design speed of 350 km/h, both the drainage lining and the waterproof lining were controlled by a small eccentric compression under the two test conditions. One had only water pressure, and the other had a variable water pressure and constant soil pressure. The key sections for controlling instability were the bottom of the wall and the inverted arch. The ultimate water head of the drainage lining was 49 m, and the ultimate water head of the waterproof lining was 78 m. In comparison with the drainage lining, the waterproof lining could significantly improve the water-pressure resistance. Thus, design loads of 30 and 60 m are recommended for the drainage and waterproof lining structures, respectively.

Detection and Control of Building Materials Quality

2013 ◽  
Vol 791-793 ◽  
pp. 490-492
Author(s):  
Xiao Lin Dong ◽  
Dong Nan Han
Keyword(s):  
Construction Industry ◽  
Construction Projects ◽  
High Speed ◽  
Building Materials ◽  
Civil Engineering ◽  
Engineering Construction ◽  
Material Basis ◽  
Control Work ◽  
And Control

Along with the high-speed development of China's construction industry, building materials as the material basis of civil engineering construction, the quality of building materials is directly related to the quality of construction projects, so the good building materials quality, particularly important to detect and control work. In this paper, combined with the author's working practice, discusses how to do detection and control the quality of building materials should pay attention to the problem.

Dynamic Accumulation Damage Characteristics of Initial Cracks for the Lining of High-Speed Railway’s Tunnel

2014 ◽  
Vol 580-583 ◽  
pp. 1311-1314
Author(s):  
Xiang Qiu Wang ◽  
Bin Cai
Keyword(s):  
High Speed ◽  
Damage Zone ◽  
Damage Mechanism ◽  
Initial Crack ◽  
Tunnel Lining ◽  
Railway Tunnel ◽  
Limit Values ◽  
Lining Structure ◽  
Initial Cracks

After have been analysed the initial dynamic cumulative damage mechanism of lining structure of the high speed railway tunnel,the conclusions have been gained that, under the effect of the long-term vibrating load of high speed train, When the damage energy accumulation reached a limit values, the damage zone caused by the initial crack which has been existed in the tunnel lining will be expansed further more. for the more, based on the accumulation damage theory linear elasticity and the analysis method dynamic finite element, The extension characters and calculation method of initail crack in the tunnel lining structures for the high railway have been proposed.

scholarly journals The vibration characteristic and impact analysis of the tunnel lining detection device based on arc rotating multi-section mechanism

2020 ◽  
Vol 12 (4) ◽  
pp. 168781402091297
Author(s):  
Yang Lei ◽  
Tian Tian
Keyword(s):  
High Speed ◽  
Impact Analysis ◽  
Simulation Analysis ◽  
Detection Efficiency ◽  
Longitudinal Vibration ◽  
Dynamic Test ◽  
Tunnel Lining ◽  
Railway Tunnel ◽  
Technical Requirements ◽  
Radar Antennas

In order to overcome the great interference of many ancillary facilities in the process of tunnel lining detection, a vehicle-borne high-speed railway tunnel lining detection device was designed based on the arc rotation mechanism to improve the detection efficiency and quality. The device could automatically maintain the antenna–lining distance and carry three radar antennas at one time, which detected the tunnel from the side of the catenary frame without stopping. Through the establishment of the mechanism three-dimensional finite element model, the simulation and analysis of natural frequency and vibration characteristics were carried out, and the results were confirmed by the field dynamic test. It is concluded that the dynamic characteristics can meet the technical requirements under the radial and the longitudinal vibration at 5 km h−1, but the detection data quality of the three radar antennas under the radial vibration is quite different. After optimizing the bent arm material to carbon fiber, the dynamic stability of the mechanism is significantly improved through simulation analysis and the detection speed can be increased to 10 km h−1 with a substantial leap.

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