ASSESSING THE INFLUENCE OF MODIFICATIONS ON IN-SERVICE PERFORMANCE OF STRUCTURAL SYSTEMS USING VIBRATION MEASUREMENTS

2009 ◽  
Vol 09 (04) ◽  
pp. 729-744
Author(s):  
NICHOLAS HARITOS
Keyword(s):  
Model Updating ◽  
Dynamic Testing ◽  
Service Condition ◽  
Pile Group ◽  
Integrity Assessment ◽  
Wrought Iron ◽  
System A ◽  
Pass Through ◽  
And Performance ◽  
Floor System

This paper outlines application of dynamic testing to three separate structures where evaluations of their in-service condition and performance were required. In two of these cases, both bridges, model updating procedures enabled identification of key structural properties for performing an integrity assessment. In the case of the first bridge, dynamic testing was able to demonstrate that the first attempt at introducing bandbeams to strengthen the bridge over its piers was virtually ineffective in stiffening the bridge. However, after these bandbeams were replaced, similar dynamic testing verified that the new work was now in fact so effective in stiffening this same bridge. Dynamic testing of the second bridge, a historical wrought iron swing bridge, was able to verify the integrity of the central pile group about which this bridge swings to allow riverboats to pass through. For the third case, involving a specialist laboratory floor system, a variety of excitation options were exercised to establish the acceptability of the floor to stringent criteria on vibration response levels.

Application Fuzzy Logic System for Accurate Sheet Trim Shower Position

2019 ◽  
Vol 3 (1) ◽  
pp. 186-192
Author(s):  
Yudi Wibawa
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Dc Motor ◽  
Automation System ◽  
Paper Making ◽  
System A ◽  
Accurate Position ◽  
And Performance ◽  
Better Than ◽  
Logic System

This paper aims to study for accurate sheet trim shower position for paper making process. An accurate position is required in an automation system. A mathematical model of DC motor is used to obtain a transfer function between shaft position and applied voltage. PID controller with Ziegler-Nichols and Hang-tuning rule and Fuzzy logic controller for controlling position accuracy are required. The result reference explains it that the FLC is better than other methods and performance characteristics also improve the control of DC motor.

scholarly journals Modeling and Implementation of MPPT based Wind Energy System Using Cuckoo Search

2018 ◽  
Vol 7 (2.7) ◽  
pp. 671
Author(s):  
Kaleem SK ◽  
Rama Subbanna S
Keyword(s):  
Wind Energy ◽  
Control Strategy ◽  
Cuckoo Search ◽  
Energy System ◽  
System A ◽  
Wind Turbine System ◽  
Proposed Model ◽  
Wind Energy System ◽  
Mppt Controller ◽  
And Performance

This paper presents adjustable speed generators for wind turbines. In order to improve the potential and performance of wind turbine system this paper proposes a concept DFIG. Generally wind nature is not fixed it varies linearly w.r.t time, hence, a MPPT controller is proposed in this paper. This paper presents the DFIG wind energy system. A Control strategy implemented and controlled by framing rotor reference frame axis in terms of direct and quadrature axis coordinates. A PI based RSC and GSC controllers are introduced to control the power through the wind system to grid. This proposed model is implemented and verified by using Matlab/Simulink.  

scholarly journals Three Phase Resolution Transmitarray Element for Electronically Reconfigurable Transmitarrays

2019 ◽  
Vol 2019 (2) ◽  
pp. 106-113
Author(s):  
Nguyễn Minh Thiện ◽  
Nguyễn Hữu Minh ◽  
Nguyễn Bình Dương
Keyword(s):  
Phase Change ◽  
Phase State ◽  
Main Beam ◽  
System A ◽  
Full Wave ◽  
Three Phase ◽  
Phase Resolution ◽  
Waveguide System ◽  
Em Simulation ◽  
And Performance

Electrical beam scanning is a feature enabling an antenna array to electrically control its main beam toward a desired direction. In this paper, a three-phase state element for electronically reconfigurable transmitarrays is presented. The element is made up of C-patches and modified ring slots loaded rectangular gaps. By controlling the bias state of four p-i-n diodes, three phase states are obtained. The dimension of the element is optimized by using full-wave EM simulation and performance of the element is validated by both simulation and an experimental waveguide system. A transmitarrayconsistingof12×12elementshasbeensimulated to validate the steering capabilities. Experimental results indicate the element has good characteristics and excellent phase change capabilities.

Aerobic Evaluation in Elite Slalom Kayakers Using a Tethered Canoe System: A New Proposal

2017 ◽  
Vol 12 (7) ◽  
pp. 864-871
Author(s):  
Homero Gustavo Ferrari ◽  
Leonardo H.D. Messias ◽  
Ivan G.M. Reis ◽  
Claudio A. Gobatto ◽  
Filipe A.B. Sousa ◽  
...  
Keyword(s):  
Low Cost ◽  
Critical Force ◽  
Noninvasive Method ◽  
Maximal Lactate Steady State ◽  
National Team ◽  
System A ◽  
And Performance ◽  
The Relationship ◽  
New Strategies ◽  
Aerobic Evaluation

Background:Among other aspects, aerobic fitness is indispensable for performance in slalom canoe.Purpose:To propose the maximal-lactate steady-state (MLSS) and critical-force (CF) tests using a tethered canoe system as new strategies for aerobic evaluation in elite slalom kayakers. In addition, the relationship between the aerobic parameters from these tests and the kayakers’ performances was studied.Methods:Twelve male elite slalom kayakers from the Brazilian national team participated in this study. All tests were conducted using a tethered canoe system to obtain the force records. The CF test was applied on 4 d and analyzed by hyperbolic (CFhyper) and linear (CFlin) mathematical models. The MLSS intensity (MLSSint) was obtained by three 30-min continuous tests. The time of a simulated race was considered the performance index.Results:No difference (P < .05) between CFhyper (65.9 ± 1.6 N) and MLSSint (60.3 ± 2.5 N) was observed; however, CFlin (71.1 ± 1.7 N) was higher than MLSSint. An inverse and significant correlation was obtained between MLSSint and performance (r = –.67, P < .05).Conclusion:In summary, MLSS and CF tests on a tethered canoe system may be used for aerobic assessment of elite slalom kayakers. In addition, CFhyper may be used as an alternative low-cost and noninvasive method to estimate MLSSint, which is related with slalom kayakers’ performance.

Factors affecting changes in rheological properties of blood – literature review

2017 ◽  
Vol 53 (4) ◽  
pp. 247-250
Author(s):  
Magdalena Kępińska ◽  
Zbigniew Szyguła ◽  
Zbigniew Dąbrowski ◽  
Marta Szarek
Keyword(s):  
Rheological Properties ◽  
Scientific Literature ◽  
Vascular System ◽  
The Elderly ◽  
Physiological Factors ◽  
Factors Affecting ◽  
System A ◽  
High Elasticity ◽  
Pass Through ◽  
Biochemical Indices

Erythrocytes have high elasticity and the ability to build blood aggregates, they can pass through the smallest capillaries, thus ensuring the transport of oxygen and carbon dioxide in all areas of the vascular system. A decrease in the deformability of erythrocytes may result in reduced blood flow and thereby the cause of many diseases. The increase in blood viscosity is observed, among others, in diabetes, hypertension, obesity and the elderly. Rheological studies of blood in conjunction with morphological and biochemical indices of blood provide valuable information about health of the patient. Any change in the viscosity of blood or plasma should be monitored, as this may indicate a health problem. The aim of the study was to present, based on the available scientific literature, physiological factors influencing changes in rheological properties of blood, for example: exercise, temperature and body weight

Numerical and Experimental Assessment of the Highway Arch Viaduct

2015 ◽  
Vol 769 ◽  
pp. 252-259
Author(s):  
Jan Bencat ◽  
Maria Stehlikova ◽  
Milan Skarupa
Keyword(s):  
Dynamic Testing ◽  
Highway Bridges ◽  
Structural Condition ◽  
Traffic Load ◽  
Analytical Models ◽  
Mode Shapes ◽  
Bridge Structure ◽  
Modal Damping ◽  
Bridge Structures ◽  
And Performance

Full–scale dynamic testing of bridge structures can provide valuable information on the service behavior and performance of structures. With the growing interest in the structural condition of highway bridges, dynamic testing can be used as a tool for assessing the integrity of bridges. From the measured dynamic response, induced by instructed passing trucks, modal parameters (natural frequencies, mode shapes and modal damping values) and system parameters (stiffness, mass and damping matrices) are obtained. These identified parameters can then be used to characterize and monitor the service of the bridge structure in the future. Analytical models of the structure can also be validated using these parameters [1,2]. The paper presents a procedure for estimating the traffic load bearing capacity of the steel arch highway viaduct Bridge Structure 205 (DC1–9, 755 m) constructed on Highway D1 in Nord Slovakia (Fig. 1) over the natural hollow basin via dynamic tests of the viaduct structures.

New Options for the Microsurgeon

Neurosurgery ◽  
1981 ◽  
Vol 9 (5) ◽  
pp. 566-572 ◽  
Author(s):  
I. M. Greenberg
Keyword(s):  
Hand Movements ◽  
System A ◽  
And Performance ◽  
Microsurgical Procedure

Abstract Using the Greenberg universal retraction system, a single surgeon can control four or more microinstruments simultaneously in a single microsurgical field. By decreasing the number of hand movements heretofore required and by increasing the surgeon' biotechnological options, the entire microsurgical procedure becomes more efficient and more economical, maximizing the surgeon' capabilities and performance.

Development and Performance Study of an Apparatus for Imparting Lateral Cyclic Load on Model Pile Foundation

2006 ◽  
Author(s):  
Sudip Basak
Keyword(s):  
Pile Foundation ◽  
Cyclic Load ◽  
Pile Group ◽  
Offshore Structures ◽  
Performance Study ◽  
Model Pile ◽  
New Apparatus ◽  
Group A ◽  
And Performance ◽  
Strength And Stiffness

The environment prevalent in ocean necessitates the pile foundations supporting offshore structures to be designed against lateral cyclic loading initiated by wave action. Such quasi-static load reversal induces deterioration in the strength and stiffness of the soil-pile system introducing progressive reduction in the bearing capacity as well as settlement of the pile foundation. To understand the effect of lateral cyclic load on pile group, a new apparatus, consisting of mechanically and electrically controlled components, has been designed and fabricated. Each of the components of this apparatus is calibrated and a series of trial tests are performed for its performance study. This paper presents detailed description of the apparatus, calibration and operating principle of each of its components, the observations made from trial experiments and the relevant conclusions drawn therefrom.

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