scholarly journals Development Of Precast Barrier Wall System For Bridge Decks

2021 ◽  
Author(s):  
Gaurang Patel
Keyword(s):  
Design Procedure ◽  
Experimental Tests ◽  
Experimental Investigations ◽  
Work Zone Safety ◽  
Connection System ◽  
Bridge Joints ◽  
Design Loads ◽  
Experimental Findings ◽  
Wall System ◽  
Barrier Wall

As Ontario transportation infrastructure enters the era of maintenance, rehabilitation and replacement, it needs more use of prefabricated elements and systems, which can quickly assembled to overcome relatively longer time to open bridge to the traffic. This thesis reports on both analytical and experimental investigations conducted on various aspects of precast bridge barrier, including design loads, structural design, sequence of construction, connection details between the barriers and bridge, joints between barrier segments and water leakage control. In this study, thru post-tensioned bolted connection system was developed to connect the precast barrier wall with bridge deck. The primary intension behind these connections is to expedite construction cycle simulataneously with minimizing traffic disruption, improve work-zone safety, quality and constructible and lower down lifecycle cost of bridges. A total of five experimental tests on full-scale specimens of the developed system were conducted to verify and substantiate the design procedure used to develop the barrier wall system. Good correlation between theoretical ultimate loads, in the form of bending, shear and punching shear resistance, and the experimental findings was achieved.

scholarly journals Development Of Precast Barrier Wall System For Bridge Decks

2021 ◽  
Author(s):  
Gaurang Patel
Keyword(s):  
Design Procedure ◽  
Experimental Tests ◽  
Experimental Investigations ◽  
Work Zone Safety ◽  
Connection System ◽  
Bridge Joints ◽  
Design Loads ◽  
Experimental Findings ◽  
Wall System ◽  
Barrier Wall

As Ontario transportation infrastructure enters the era of maintenance, rehabilitation and replacement, it needs more use of prefabricated elements and systems, which can quickly assembled to overcome relatively longer time to open bridge to the traffic. This thesis reports on both analytical and experimental investigations conducted on various aspects of precast bridge barrier, including design loads, structural design, sequence of construction, connection details between the barriers and bridge, joints between barrier segments and water leakage control. In this study, thru post-tensioned bolted connection system was developed to connect the precast barrier wall with bridge deck. The primary intension behind these connections is to expedite construction cycle simulataneously with minimizing traffic disruption, improve work-zone safety, quality and constructible and lower down lifecycle cost of bridges. A total of five experimental tests on full-scale specimens of the developed system were conducted to verify and substantiate the design procedure used to develop the barrier wall system. Good correlation between theoretical ultimate loads, in the form of bending, shear and punching shear resistance, and the experimental findings was achieved.

Design of a Force Feedback Chatter Control System

1972 ◽  
Vol 94 (1) ◽  
pp. 5-10 ◽  
Author(s):  
C. Nachtigal
Keyword(s):  
Machine Tool ◽  
Frequency Domain ◽  
Transient Response ◽  
Force Feedback ◽  
Design Procedure ◽  
Experimental Tests ◽  
Work Piece ◽  
Regenerative Chatter ◽  
Chatter Control ◽  
The Stability

The analysis of machine tool chatter from frequency domain considerations is generally accepted as a valid representation of the regenerative chatter phenomenon. However, active control of regenerative chatter is still in its embryonic stage. It was established in reference [2] that a measurement of the cutting force could be effectively used in conjunction with a controller and a tool position servo system to increase the stability of an engine lathe and to improve its transient response. This paper presents the design basis for such a system, including both analytical and experimental considerations. The design procedure stems from a real part stability criterion based on the work by Merritt [1]. Because of the unknown variability in the dynamics of a machine tool system, the controller parameters were chosen to accomodate some mismatch between structure and tool servo dynamics. Experimental tests to determine the stability zone of the controlled machine tool system qualitatively confirmed the analytical design results. The experimental results were consistent in that the transient response tests confirmed the frequency domain stability tests. It was also demonstrated experimentally that the equivalent static stiffness of a flexible work-piece system could be substantially increased.

scholarly journals Modeling and Simulation of Collision-Causing Derailment to Design the Derailment Containment Provision Using a Simplified Vehicle Model

2019 ◽  
Vol 10 (1) ◽  
pp. 118 ◽  
Author(s):  
In-Ho Song ◽  
Jun-Woo Kim ◽  
Jeong-Seo Koo ◽  
Nam-Hyoung Lim
Keyword(s):  
Computation Time ◽  
Test Results ◽  
Vehicle Model ◽  
Surrounding Structure ◽  
Proposed Model ◽  
Design Loads ◽  
Simulation Results ◽  
Real Test ◽  
Great Damage ◽  
Barrier Wall

As the operating speed of a train increases, there is a growing interest in reducing damage caused by derailment and collision accidents. Since a collision with the surrounding structure after a derailment accident causes a great damage, protective facilities like a barrier wall or derailment containment provision (DCP) are installed to reduce the damage due to the secondary collision accident. However, the criteria to design a protective facility such as locations and design loads are not clear because of difficulties in predicting post-derailment behaviors. In this paper, we derived a simplified frame model that can predict post derailment behaviors in the design phase of the protective facilities. The proposed vehicle model can simplify for various frames to reduce the computation time. Also, the actual derailment tests were conducted on a real test track to verify the reliability of the model. The simulation results of the proposed model showed reasonable agreement to the test results.

scholarly journals Skew Rolling of Rods from Scrap Rail Heads

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2970 ◽  
Author(s):  
Tomczak ◽  
Pater ◽  
Bulzak
Keyword(s):  
Experimental Tests ◽  
Rolling Process ◽  
Industrial Applications ◽  
Experimental Investigations ◽  
Longitudinal Rolling ◽  
Rolling Mills ◽  
Second Stage ◽  
New Process ◽  
Skew Rolling ◽  
Theoretical Considerations

This paper presents the results of theoretical and experimental investigations of a new process of rolling rods from scrap rail heads. First, the industrial applications of scrap railway rails and methods of their recycling are discussed, and then the concept of two-stage rolling of rods from heads cut off from scrap rails is proposed. In the first stage of the process, a rail head preform was rolled in a hexagonal pass of a longitudinal rolling mill. Then in the second stage, the hexagonal bar was skew rolled into a rod in a helical roll pass. Theoretical considerations were based on finite element numerical modelling. The rolling process was simulated under 3D deformation using Forge NxT v.1.1 software developed by Transvalor Company. Calculations were carried out to determine the material flow kinematics, strength, and thermal parameters of the process and to identify the phenomena that might constrain its implementation. The numerical results were verified in experimental tests, during which preforms and rods were formed from scrap rail heads. The tests were conducted in longitudinal and skew rolling mills. The results indicate that rods can be effectively formed from scrap rail heads in just two steps. Rods obtained using the proposed method can be used as full-featured, semifinished products for the manufacture of various types of machine parts.

Influence of the Parameter of Ductility of Reinforcing Steel on the Behaviour of a Narrow Three-Span Reinforced Concrete Slab Based on Experimental Investigations

2015 ◽  
Vol 240 ◽  
pp. 218-224 ◽  
Author(s):  
Mirosław Wieczorek
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Load Capacity ◽  
Experimental Tests ◽  
Experimental Investigations ◽  
Building Structures ◽  
Reinforced Concrete Slab ◽  
Tension Member ◽  
Test Models ◽  
Reinforced Steel

In the time of the exploitation of building structures frequently situations do occur, in which due to failures they are exposed to much higher loads than has been originally predicted. In a state of emergency due to overloading of the structure, significant reserves of load capacity may be appear in the case of a self-acting tension member work. The aim of the paper was to demonstrate the influence of reinforced steel parameters and its quantity on the mechanism of destruction of four three-span models of reinforced concrete strips with the dimensions 7140×500×190 mm. The paper contains the description of the test stand and test models and the results of experimental tests which were compared with the results of the calculations based on traditional methods.

Determination of Engine Roughness Using Multi-Physics Numerical Predictions

2005 ◽  
Author(s):  
M. Perera ◽  
S. Theodossiades ◽  
H. Rahnejat
Keyword(s):  
Film Formation ◽  
Structural Deformation ◽  
Experimental Investigations ◽  
Tribological Behaviour ◽  
Load Bearing ◽  
Numerical Predictions ◽  
Engine Design ◽  
Model Predictions ◽  
Simplifying Assumptions ◽  
Experimental Findings

The paper presents a detailed engine modelling method, referred to as a multi-physics approach, in which combined rigid body inertial dynamics, structural modal characteristics of elastic components and tribological behaviour of load bearing surfaces can be studied within a single analysis. This approach is regarded as holistic and a good aid for detailed design. Of particular interest is the evaluation of behaviour of critical elements in the system, such as the load bearing conjunctions (e.g. crankshaft engine bearings). Another important feature is the inclusion of study of motion across the physics of scale, from micro-scale fluid film formation in bearings to sub-millimetre structural deformation of components and large displacement inertial dynamics. In order to arrive at predictions within sensible industrial time scales, it is essential to include, as far as possible, modelling features of analytical rather than numerical nature, which necessitates inclusion of some simplifying assumptions. When such an undertaking is made, the validity of model predictions must be gauged against experimental findings to enhance confidence in the use of the method. The paper shows good conformance between model predictions and experimental investigations. It further shows that some important issues in engine design and development can be addressed in a satisfactory manner, paving the way for reduction in the empirical or iterative nature of engine design evaluation.

scholarly journals Performance Evaluation of Multi-UAV Network Applied to Scanning Rocket Impact Area

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4895
Author(s):  
Maurício R. Silva ◽  
Elitelma S. Souza ◽  
Pablo J. Alsina ◽  
Deyvid L. Leite ◽  
Mateus R. Morais ◽  
...  
Keyword(s):  
Communication Network ◽  
Communication Networks ◽  
Network Architecture ◽  
Design Procedure ◽  
Data Communication ◽  
Experimental Tests ◽  
Network Nodes ◽  
Communication Links ◽  
Impact Area ◽  
Multi Uav

This paper presents a communication network for a squadron of unmanned aerial vehicles (UAVs) to be used in the scanning rocket impact area for Barreira do Inferno Launch Center—CLBI (Rio Grande do Norte, Brazil), aiming at detecting intruder boats. The main features of communication networks associated with multi-UAV systems are presented. This system sends information through Wireless Sensor Networks (WSN). After comparing and analyzing area scanning strategies, it presents the specification of a data communication network architecture for a squadron of UAVs within a sensor network using XBee Pro 900HP S3B modules. A brief description is made about the initial information from the construction of the system. The embedded hardware and the design procedure of a dedicated communication antenna to the XBee modules are presented. In order to evaluate the performance of the proposed architecture in terms of robustness and reliability, a set of experimental tests in different communication scenarios is carried out. Network management software is employed to measure the throughput, packet loss and other performance indicators in the communication links between the different network nodes. Experimental results allow verifying the quality and performance of the network nodes, as well as the reliability of the communication links, assessing signal received quality, range and latency.

scholarly journals Displacement Study of a Large-Scale Freeform Timber Plate Structure Using a Total Station and a Terrestrial Laser Scanner

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 413 ◽  
Author(s):  
Anh Chi Nguyen ◽  
Yves Weinand
Keyword(s):  
Large Scale ◽  
Numerical Models ◽  
Laser Scanner ◽  
Experimental Tests ◽  
Point Clouds ◽  
Element Model ◽  
Experimental Investigations ◽  
Bottom Surface ◽  
Terrestrial Laser Scanner ◽  
Total Station

Recent advances in timber construction have led to the realization of complex timber plate structures assembled with wood-wood connections. Although advanced numerical modelling tools have been developed to perform their structural analysis, limited experimental tests have been carried out on large-scale structures. However, experimental investigations remain necessary to better understand their mechanical behaviour and assess the numerical models developed. In this paper, static loading tests performed on timber plate shells of about 25 m span are reported. Displacements were measured at 16 target positions on the structure using a total station and on its entire bottom surface using a terrestrial laser scanner. Both methods were compared to each other and to a finite element model in which the semi-rigidity of the connections was represented by springs. Total station measurements provided more consistent results than point clouds, which nonetheless allowed the visualization of displacement fields. Results predicted by the model were found to be in good agreement with the measurements compared to a rigid model. The semi-rigid behaviour of the connections was therefore proven to be crucial to precisely predict the behaviour of the structure. Furthermore, large variations were observed between as-built and designed geometries due to the accumulation of fabrication and construction tolerances.

Mathematical models and experimental data for HDF based sandwich panels with dual corrugated lightweight core

Holzforschung ◽  
2017 ◽  
Vol 71 (3) ◽  
pp. 265-273 ◽  
Author(s):  
Jerzy Smardzewski ◽  
Dorota Jasińska
Keyword(s):  
Homogeneous Model ◽  
Sandwich Panels ◽  
Experimental Tests ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Experimental Investigations ◽  
Calculation Results ◽  
Orthotropic Properties ◽  
Auxetic Structure ◽  
Lightweight Core

Abstract Light layer honeycomb panels could replace traditional wood materials, if their stiffness and strength properties could be improved. The aim of this research was to design and determine elastic properties of sandwich panels (SPs) based on a dual corrugated HDF core. Stiffness matrix values of elements were determined by a numerical method. The 3D calculation results were compared with those of the homogeneous model. The calculation results were collated with those of experimental investigations. It was demonstrated that the linear elasticity modulus as well as the modulus of rupture of the SPs were comparable with mechanical properties of a particle board with identical thickness, while the SP has a 1/3 lower density. The panel core exhibited significant orthotropic properties. In the xy plane it could be characterized as an auxetic structure. The homogeneous model leads to results similar to those achieved from the 3D model and observed in experimental tests.

scholarly journals Hydrogen production from ethanol in nitrogen microwave plasma at atmospheric pressure

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Bartosz Hrycak ◽  
Dariusz Czylkowski ◽  
Robert Miotk ◽  
Miroslaw Dors ◽  
Mariusz Jasinski ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Atmospheric Pressure ◽  
Alternative Energy ◽  
Coal Gasification ◽  
Microwave Plasma ◽  
Atmospheric Pressure Plasma ◽  
Water Electrolysis ◽  
Experimental Tests ◽  
Experimental Investigations ◽  
Promising Alternative

AbstractHydrogen seems to be one of the most promising alternative energy sources. It is a renewable fuel as it could be produced from e.g. waste or bio-ethanol. Furthermore hydrogen is compatible with fuel cells and is environmentally clean. In contrast to conventional methods of hydrogen production such as water electrolysis or coal gasification we propose a method based on atmospheric pressure microwave plasma. In this paper we present results of the experimental investigations of hydrogen production from ethanol in the atmospheric pressure plasma generated in waveguide-supplied cylindrical type nozzleless microwave (2.45 GHz) plasma source (MPS). Nitrogen was used as a working gas. All experimental tests were performed with the nitrogen flow rate Q ranged from 1500 to 3900 NL h

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