scholarly journals Method to Increase the Accuracy of Large Crankshaft Geometry Measurements Using Counterweights to Minimize Elastic Deformations

2020 ◽  
Vol 10 (14) ◽  
pp. 4722 ◽  
Author(s):  
Leszek Chybowski ◽  
Krzysztof Nozdrzykowski ◽  
Zenon Grządziel ◽  
Andrzej Jakubowski ◽  
Wojciech Przetakiewicz
Keyword(s):  
Elastic Deformation ◽  
Measurement System ◽  
Design Solution ◽  
Structural Elements ◽  
Elastic Deformations ◽  
Elastic Deflection ◽  
Reaction Forces ◽  
Geometry Measurement

Large crankshafts are highly susceptible to flexural deformation that causes them to undergo elastic deformation as they revolve, resulting in incorrect geometric measurements. Additional structural elements (counterweights) are used to stabilize the forces at the supports that fix the shaft during measurements. This article describes the use of temporary counterweights during measurements and presents the specifications of the measurement system and method. The effect of the proposed solution on the elastic deflection of a shaft was simulated with FEA, which showed that the solution provides constant reaction forces and ensures nearly zero deflection at the supported main journals of a shaft during its rotation (during its geometry measurement). The article also presents an example of a design solution for a single counterweight.

The study of the elastic deformation of a flexible wheel by a cam wave generator

2020 ◽  
Vol 65 (1) ◽  
pp. 51-58
Author(s):  
Sava Ianici
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Elastic Deformation ◽  
Theoretical Study ◽  
Elastic Field ◽  
The Finite Element Method ◽  
Elastic Deformations ◽  
Wave Generator ◽  
Two Stages

The paper presents the results of research on the study of the elastic deformation of a flexible wheel from a double harmonic transmission, under the action of a cam wave generator. Knowing exactly how the flexible wheel is deformed is important in correctly establishing the geometric parameters of the wheels teeth, allowing a better understanding and appreciation of the specific conditions of harmonic gearings in the two stages of the transmission. The veracity of the results of this theoretical study on the calculation of elastic deformations and displacements of points located on the average fiber of the flexible wheel was subsequently verified and confirmed by numerical simulation of the flexible wheel, in the elastic field, using the finite element method from SolidWorks Simulation.

FRA Autonomous Track Geometry Measurement System Technology Development: Past, Present, and Future

2014 ◽  
Author(s):  
Soheil Saadat ◽  
Cameron Stuart ◽  
Gary Carr ◽  
James Payne
Keyword(s):  
Research And Development ◽  
Measurement System ◽  
Research Program ◽  
Life Cycle Cost ◽  
Technology Development ◽  
Web Based ◽  
Track Geometry ◽  
Measurement Systems ◽  
Geometry Measurement ◽  
Multi Phase

The Federal Railroad Administration’s (FRA’s) Office of Research and Development has undertaken a multi-phase research program focused on the development and advancement of Autonomous Track Geometry Measurement Systems (ATGMS) and related technologies to improve rail safety by increasing the availability of track geometry data for safety and maintenance planning purposes. Benefits of widespread use of ATGMS technology include reduced life-cycle cost of inspection operations, minimized interference with revenue operations, and increased inspection frequencies. FRA’s Office of Research and Development ATGMS research program results have demonstrated that the paradigm of track inspection and maintenance practices, information management and, eventually, government regulations will change as a result of widespread use of ATGMS technology by the industry. A natural consequence of increased inspection frequencies associated with ATGMS is the large amount of actionable information produced. Therefore, changing existing maintenance practices to address a larger number of identified track issues across large geographic areas will be a challenge for the industry. In addition, managing ATGMS data and assessing the quality of this information in a timely manner will be challenging. This paper presents an overview of the FRA’s ATGMS research program with emphasis on its evolution from a proof-of-concept prototype to a fully operational measurement system. It presents the evolution of ATGMS technology over time including the development of a web-based application for data editing, management and quality assurance. Finally, it presents FRA’s vision for the future of the ATGMS technology.

New Deployable Structures Based on an Elastic Origami Model

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Kazuya Saito ◽  
Akira Tsukahara ◽  
Yoji Okabe
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Simple Model ◽  
Elastic Deformation ◽  
Initial Strain ◽  
New Method ◽  
The Finite Element Method ◽  
Deployable Structures ◽  
Elastic Deformations ◽  
Plate Models

Traditionally, origami-based structures are designed on the premise of “rigid folding,” However, every act of folding and unfolding is accompanied by elastic deformations in real structures. This study focuses on these elastic deformations in order to expand origami into a new method of designing morphing structures. The authors start by proposing a simple model for evaluating elastic deformation in nonrigid origami structures. Next, these methods are applied to deployable plate models. Initial strain is introduced into the elastic parts as actuators for deployment. Finally, by using the finite element method (FEM), it is confirmed that the proposed system can accomplish the complete deployment in 3 × 3 Miura-or model.

The Experimental Observation of the Prestress Forces in the Structural Elements of a Tension Fabric Structure

2013 ◽  
Vol 486 ◽  
pp. 189-194 ◽  
Author(s):  
Petr Fajman ◽  
Michal Polak ◽  
Jiří Maca ◽  
Tomáš Plachy
Keyword(s):  
Experimental Observation ◽  
Measurement System ◽  
Geometrical Nonlinearity ◽  
Structural Elements ◽  
Frequency Method ◽  
Temperature Changes ◽  
Fabric Structure ◽  
Cable Forces ◽  
Non Destructive

The periodic experimental observation of the prestress forces in some selected structural elements of the tension fabric structure is mentioned in this paper. The described experiment was focused to the tension fabric roof which covers the tram stop K Barrandovu in Prague. So far the observation was performed three times and it was every time aimed on three types of basic structural elements support cables anchored to the ground, edge cables placed in a fabric pocket and fabric membranes. The used non-destructive experimental procedures are based on the geometrical nonlinearity and the frequency method, the applied measurement system was developed by authors. The dependence of cable forces on temperature changes can be found out from the obtained results.

Hydroelastic Behavior of Air-Supported Flexible Floating Structures

2002 ◽  
Author(s):  
Tomoki Ikoma ◽  
Koichi Masuda ◽  
Hisaaki Maeda ◽  
Chang-Kyu Rheem
Keyword(s):  
Pressure Distribution ◽  
Energy Absorption ◽  
Elastic Deformation ◽  
Wave Energy ◽  
Distribution Method ◽  
Elastic Deformations ◽  
Floating Structures ◽  
Air Chamber ◽  
Air Cushion ◽  
Offshore Field

A pontoon type very large floating structure has elastic deformations in ocean waves. The deformation is larger than that of a semi-submergible type one. Thus, a pontoon type one will be installed to tranquil shallow water field enclosed by breakwaters. Moreover, a semi-submergible one will be applicable to development at offshore field. The authors has developed a pontoon type VLFS with an OWC (oscillating water column) type wave energy absorption system. This can be install to offshore field being deep water relatively. Such VLFS can reduce not only the elastic deformation but also the wave drifting forces. However, it is very difficult to reduce the wave drifting forces effectively because an effect of the reduction depends on the wave energy absorption. Therefore, the authors propose an air supported type VLFS. This idea has been already proposed. However, it wasn’t handled a flexible structure. Such an air-supported structure makes to transmit many waves. Therefore, the wave drifting forces may not increase. In addition, the elastic deformation may decrease because pressure distribution due to the incident waves becomes constant at the bottom of the structure, i.e. the pressure is constant in a same air chamber. We develop the program code for the analysis of the hydrodynamic forces on the VLFS with the air cushion. The potential flow theory is applied and the pressure distribution method is used to the analysis of the wave pressures. The zero-draft is assumed in this method. The pressure and volume change of the air cushion are linearized. In this paper, basic characteristics of the elastic deformations of the air-supported flexible floating structures are investigated. We confirm the effectiveness, and discuss behaviors of the water waves in air chamber areas.

Development of an Unattended Track Geometry Measurement System

2010 ◽  
Author(s):  
Graham Scott ◽  
Ema Chillingworth ◽  
Matthew Dick
Keyword(s):  
Measurement System ◽  
Cost Effective ◽  
Modular System ◽  
Integrated Analysis ◽  
Management Options ◽  
Operational Conditions ◽  
Track Geometry ◽  
Track Maintenance ◽  
Geometry Measurement ◽  
And Control

Compliance with track standards and control of maintenance costs are critical aspects of the management of railroads. To facilitate this, track geometry measurement systems have evolved to allow monitoring of key track geometry parameters from moving trains. This paper describes how DeltaRail’s Trackline Two™ track geometry measurement system has been developed to overcome key technical shortcomings in existing systems. The resulting step change provides a cost-effective, robust, compact measurement system suitable for use on the broadest possible range of rail vehicles and networks, from a tram to a TGV. Extensive testing has demonstrated full compliance with appropriate standards. Significant improvements in reliability and repeatability of data have enabled DeltaRail to produce a modular system capable of sending data direct to value-adding analysis tools such as TrackMaster™ and VAMPIRE® so that track maintenance management can be optimized around train fleet and operational conditions. The system is easily operated in unattended mode allowing collection of track geometry data from in-service trains, increased frequency of data collection, and pointing the way for the track maintainers to realize significant value from integrated analysis and management options.

Workpiece Deflection Compensation Using a Two-Dimensional Toolposts

2005 ◽  
Vol 219 (4) ◽  
pp. 393-400
Author(s):  
W Y Yan ◽  
A M Al-Jumaily
Keyword(s):  
Surface Roughness ◽  
Simulation Model ◽  
Active Control ◽  
Elastic Deformation ◽  
Two Dimensional ◽  
Turning Process ◽  
Elastic Deflection

Considering the workpiece elastic deflection in a turning process, a simulation model that accounts for the radial and tangential vibrations and their abatement using active control is developed. The model is simulated using Simulink in a Matlab environment to assess the possibility of using an active actuator to reduce vibrations in two directions. The results demonstrate the significance of the workpiece elastic deformation and its compensation using active actuators. Actuators that can compensate for the piece deflection and the vibrations due to the surface roughness are speculated upon.

scholarly journals CRITERIA FOR EVALUATION OF VENTILATED FACES QUALITY

2017 ◽  
Vol 7 (2) ◽  
pp. 4-8
Author(s):  
Kristina A. NETISHINA ◽  
Galina N. RYAZANOVA
Keyword(s):  
Building Construction ◽  
Design Solution ◽  
Structural Elements ◽  
Climatic Impact ◽  
Reliability Indicators ◽  
Operation Conditions ◽  
Reliability Indicator ◽  
Criteria For Evaluation ◽  
New Buildings ◽  
Account Temperature

The article describes an approach to probabilistic and physical modeling of walling reliability taking into account temperature, moisture and operation conditions, structural elements load specifi cation, reliability indicators and failure probability. The durability (service life) is taken as the main reliability indicator. The man-made and climatic impact on building construction durability is studied. It is proved that ventilated faces are a modern design solution for construction of new buildings as well as reconstruction.

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