scholarly journals Application of Laser Vibrometer to the Measurement and Control of Cable Tensile Forces in Cable-Stayed Bridges

2012 ◽  
Vol 8 (10) ◽  
pp. 810682 ◽  
Author(s):  
Cheol-Hwan Kim ◽  
Byung-Wan Jo ◽  
Jin-Taek Jun
Keyword(s):  
Tensile Force ◽  
Indirect Measurement ◽  
Laser Vibrometer ◽  
Data Logger ◽  
Long Span Bridges ◽  
Long Span ◽  
Tensile Forces ◽  
And Control ◽  
Measurement And Control

The tensile forces acting on the cable of long-span bridges are one of the most important factors since they reflect not only the structural stability of cables but also the overall quality of construction. Currently, indirect measurement using accelerometers attached to the surface of the cable is widely used to measure the natural frequency of cable. The frequency obtained from the accelerometer is converted to the tensile force of the cable. However, it sometimes requires many hazardous labors such as attaching the device on the surface of cable and wiring it with data logger, which could hinder the safety of workers during the erection of cables. In this study, a method using laser vibrometer is introduced to measure the tensile forces on cables at a distance. In addition, this study developed a unique postanalysis computer program that can calculate the tensile forces in real time. Compared with the values obtained from the accelerometers, the laser vibrometer system provided accurate and reliable matching.

The Measurement and Control of Cable Tensile Forces in Cable-Stayed Bridge using Laser Vibrometer

2012 ◽  
Vol 18 (9) ◽  
pp. 1410-1416
Author(s):  
Dongwoan Kim ◽  
Jintaek Jun ◽  
Cheolhwan Kim ◽  
Donggeun Ahn ◽  
Byungsu Kim
Keyword(s):  
Laser Vibrometer ◽  
Cable Stayed Bridge ◽  
Tensile Forces ◽  
And Control ◽  
Measurement And Control

Flutter mitigation of a superlong-span suspension bridge with a double-deck truss girder through wind tunnel tests

2020 ◽  
pp. 107754632094615
Author(s):  
Yanguo Sun ◽  
Yongfu Lei ◽  
Ming Li ◽  
Haili Liao ◽  
Mingshui Li
Keyword(s):  
Wind Tunnel ◽  
Damping Ratio ◽  
Suspension Bridge ◽  
Wind Tunnel Tests ◽  
Long Span Bridges ◽  
Long Span ◽  
Upper Deck ◽  
Torsional Damping ◽  
And Control ◽  
Wind Induced Vibration

As flutter is a very dangerous wind-induced vibration phenomenon, the mitigation and control of flutter are crucial for the design of long-span bridges. In the present study, via a large number of section model wind tunnel tests, the flutter performance of a superlong-span suspension bridge with a double-deck truss girder was studied, and a series of aerodynamic and structural measures were used to mitigate and control its flutter instability. The results show that soft flutter characterized by a lack of an evident divergent point occurred for the double-deck truss girder. Upper central stabilizers on the upper deck, lower stabilizers below the lower deck, and horizontal flaps installed beside the bottoms of the sidewalks are all effective in suppressing flutter for this kind of truss girder. By combining the structural design with aerodynamic optimizations, a redesigned truss girder with widened upper carriers and sidewalks, and double lower stabilizers combined with the inspection vehicle rails is identified as the optimal flutter mitigation scheme. It was also found that the critical flutter wind speed increases with the torsional damping ratio, indicating that the dampers may be efficient in controlling soft flutter characterized by single-degree-of-freedom torsional vibration. This study aims to provide a useful reference and guidance for the flutter design optimization of long-span bridges with double-deck truss girders.

scholarly journals Measurement and analysis of parameters of the precise grinding system

2019 ◽  
Vol 254 ◽  
pp. 01012
Author(s):  
Krzysztof Tyszczuk ◽  
Kazimierz Peszyński ◽  
Adam Mroziński ◽  
Grzegorz Śmigielski
Keyword(s):  
Laboratory Tests ◽  
Pneumatic Conveying ◽  
Air Velocity ◽  
Measurement And Control System ◽  
Diet Supplements ◽  
Measurement And Analysis ◽  
And Control ◽  
Measurement And Control ◽  
Grinding System

The technological process of materials grinding, especially biological material with high oil content, is quite complex. There are several parameters that impact the performance and quality of the process (e.g. temperature, rotational speed). One of them is the air velocity at pneumatic conveying of grinding particles. The phenomena of pneumatic transport of seeds and its impact on product’s quality and grinding capacity is not methodologically recognized so far. The paper presents the construction details of measurement and control system and results of the research obtained during the laboratory tests. The results of the tests and their analysis will be used for design of a commercial precise grinder, which allowed to reach the optimum product’s capacity and quality, constituting the basis for biological diet supplements.

scholarly journals Field Application of Cable Tension Estimation Technique Using the h-SI Method

2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
Myung-Hyun Noh ◽  
WooYoung Jung
Keyword(s):  
Tensile Force ◽  
Optimal Solution ◽  
Field Application ◽  
Theoretical Formulation ◽  
Long Span Bridges ◽  
Long Span ◽  
Identification Technique ◽  
Actual Field ◽  
Force Variation ◽  
Microgenetic Algorithm

This paper investigates field applicability of a new system identification technique of estimating tensile force for a cable of long span bridges. The newly proposed h-SI method using the combination of the sensitivity updating algorithm and the advanced hybrid microgenetic algorithm can allow not only avoiding the trap of local minimum at initial searching stage but also finding the optimal solution in terms of better numerical efficiency than existing methods. First, this paper overviews the procedure of tension estimation through a theoretical formulation. Secondly, the validity of the proposed technique is numerically examined using a set of dynamic data obtained from benchmark numerical samples considering the effect of sag extensibility and bending stiffness of a sag-cable system. Finally, the feasibility of the proposed method is investigated through actual field data extracted from a cable-stayed Seohae Bridge. The test results show that the existing methods require precise initial data in advance but the proposed method is not affected by such initial information. In particular, the proposed method can improve accuracy and convergence rate toward final values. Consequently, the proposed method can be more effective than existing methods in terms of characterizing the tensile force variation for cable structures.

Design of Measurement and Control System for the Rail Fastening Spring Clip Type A and B

2011 ◽  
Vol 299-300 ◽  
pp. 1194-1197
Author(s):  
Yu Peng Yao ◽  
Ying Shi ◽  
Yong Ping Song
Keyword(s):  
Control System ◽  
Geometric Parameter ◽  
Type A ◽  
Geometric Parameters ◽  
Measuring Instrument ◽  
Measurement And Control System ◽  
And Control ◽  
Measurement And Control

The measurement and control system is designed to control the measuring instrument which measures the geometric parameters of rail fastening spring clips. The structure and work principle of the measurement and control system are presented. Nine geometric parameters of a rail fastening spring clip which is installed only one time can be measured atomically. The limited errors of measured parameters are largely smaller than one tenth of the geometric parameter tolerance. It only spends 40 seconds to measure a rail fastening spring clip. It improves the quality of the rail fastening spring clip production and ensures that it is safe and reliably used in railway.

scholarly journals The prototype of a thermoregulatory system for measurement and control of temperature inside prosthetic socket

2016 ◽  
Vol 40 (6) ◽  
pp. 751-755 ◽  
Author(s):  
Kamiar Ghoseiri ◽  
Yong Ping Zheng ◽  
Louis Lee Tat Hing ◽  
Mohammad Reza Safari ◽  
Aaron KL Leung
Keyword(s):  
Thermal Equilibrium ◽  
Thermal Inertia ◽  
Thermal Capacity ◽  
Residual Limb ◽  
Phantom Model ◽  
Prosthetic Socket ◽  
Thermoregulatory System ◽  
And Control ◽  
Measurement And Control

Background and aim: Thermal related problems with prostheses are common complaints of amputee people. This article aims to introduce a thermoregulatory technique as a potential solution for those problems in prostheses wearers. Technique: A smart thermoregulatory system was designed, manufactured, and installed on a phantom model of a prosthetic socket. It captured temperature data from 16 sensors positioned at the interface between the phantom model and a silicone liner and used their average for comparison with a defined set temperature to select required heating or cooling functions for thermal equilibrium. A thin layer of Aluminum was used to transfer temperature between thermal pump and different sites around the phantom model. Discussion: The feasibility of this thermoregulatory technique was confirmed by its ability to provide thermal equilibrium. Further investigations to improve the design of thermoregulatory system are necessary including temperature transfer element and power consumption based on thermal capacity and thermal inertia of the residual limb. Clinical relevance The smart thermoregulatory system by providing thermal equilibrium between two sides of a prosthetic silicone liner can control residual limb skin temperature and sweating. Consequently, it can improve quality of life in amputee people.

An Estimation on the Performance of High Fluidity Anti-Washout Underwater Concrete

2013 ◽  
Vol 577-578 ◽  
pp. 501-504 ◽  
Author(s):  
Jung Jun Park ◽  
Jae Heum Moon ◽  
Jun Hyoung Park ◽  
Sung Wook Kim
Keyword(s):  
Suspended Solids ◽  
Significant Loss ◽  
High Pressure Pump ◽  
Long Span Bridges ◽  
Long Span ◽  
Slump Flow ◽  
Reverse Circulation ◽  
Underwater Concrete ◽  
Packing Ability

The placing of anti-washout underwater concrete for the increasing construction of offshore foundations of long-span bridges at relatively deep sea is accompanied with significant loss of the quality of concrete as well as of the durability and reliability of the structure due to limitations brought by the workability of the high-pressure pump and the performance of the anti-washout agent. Therefore, the improvement of the performance of the underwater anti-washout agent and the development of high fluidity anti-washout underwater concrete exhibiting improved packing ability and fluidity should be implemented. Accordingly, this study focuses on the concrete for foundations applied in the RCD (Reverse Circulation Drill) method. The adequate mix proportions of a high fluidity anti-washout underwater concrete satisfying a design compressive strength of 35 MPa, slump flow larger than 600 mm and with less than 50 mg/ℓ of suspended solids is derived and the corresponding characteristics are evaluated.

scholarly journals INDIRECT MEASUREMENT AND CONTROL OF MOISTURE CONTENT DURING DEHYDRATION PERFORMED BY FRYING

1999 ◽  
Vol 17 (7-8) ◽  
pp. 1627-1637 ◽  
Author(s):  
G. Trystram ◽  
I.C. Tréléa ◽  
A.L. Raoult-Wack ◽  
A. Diaz ◽  
F. Courtois
Keyword(s):  
Moisture Content ◽  
Indirect Measurement ◽  
And Control ◽  
Measurement And Control

scholarly journals Measurement Data Processing with the Use of Art Networks

2018 ◽  
Vol 28 (2) ◽  
pp. 186-195
Author(s):  
Maria Mrówczyńska ◽  
Jacek Sztubecki
Keyword(s):  
Measurement Data ◽  
Strong Impact ◽  
Resonance Theory ◽  
Adaptive Resonance ◽  
Control Networks ◽  
Vertical Displacements ◽  
Processing Measurement ◽  
And Control ◽  
Measurement And Control

Abstract ART (Adaptive Resonance Theory) networks were invented in the 1990s as a new approach to the problem of image classification and recognition. ART networks belong to the group of resonance networks, which are trained without supervision. The paper presents the basic principles for creating and training ART networks, including the possibility of using this type of network for solving problems of predicting and processing measurement data, especially data obtained from geodesic monitoring. In the first stage of the process of creating a prediction model, a preliminary analysis of measurement data was carried out. It was aimed at detecting outliers because of their strong impact on the quality of the final model. Next, an ART network was used to predict the values of the vertical displacements of points of measurement and control networks stabilized on the inner and outer walls of an engineering object.

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