scholarly journals Full-Scale Field Experimental Investigation on the Intended Irregularity of CWR Track in Vertical Plane

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7477
Author(s):  
Włodzimierz Andrzej Bednarek
Keyword(s):  
Static Load ◽  
Optical Measurement ◽  
Vertical Plane ◽  
Railway Track ◽  
Support Condition ◽  
Static Loads ◽  
Static And Dynamic Analysis ◽  
Field Investigations ◽  
Railway Sleeper ◽  
Locomotive Wheels

The purpose of the following paper is to present the author’s experimental field investigations of a jointless railway track subjected to a generated imperfection and analysis of track response to applied static loads. An optical measurement system, Pontos, was used for the static and dynamic analysis of the track’s deflections in 3D. The investigations allow us to recommend a direct application of this system for the non-contact measurement, visualization and analysis of simulated defects in the jointless track, as presented by the author. It is stated that simulation of an effect called the hanging sleeper, a short irregularity in the railway track with the initial parameters provided (a gap and a length of irregularity), is possible. The proposed method, based on the measurement in the loaded track (a static load from the locomotive wheels), allows for a description of the effect of the changing track support condition. Moreover, it also proves its usefulness for the analysis of the changes in deflection and stress values and the force transferred from the rail on the railway sleeper and for the assumed shape of defects simulating the short irregularities arising in the operated railway track. The arising irregularity in the track affects driving comfort and the safety of travellers.

scholarly journals Analysis of static forces generated in-track on a railway sleeper resting on an elastic foundation due to structural imperfections using the PONTOS system

2019 ◽  
Vol 262 ◽  
pp. 11001
Author(s):  
Włodzimierz Andrzej Bednarek
Keyword(s):  
Theoretical Calculations ◽  
Railway Track ◽  
Bernoulli Beam ◽  
Main Concept ◽  
Field Investigations ◽  
Railway Sleeper ◽  
Foundation Parameters ◽  
Euler Bernoulli Beam ◽  
Structural Imperfections ◽  
Two Parameter

In the paper a considered railway sleeper was analysed as an Euler-Bernoulli beam and a Timoshenko beam of finite length resting on a oneand two-parameter foundation. The foundation parameters were determined based on a modified and analogue Vlasov soil model and field investigations. The main concept for the executed investigations was to induce an intentional imperfection in an actual railway track, propose a way of appropriate measurement (e.g. the PONTOS system by GOM mbh), and utilize author’s field investigations results to calibrate necessary parameters for theoretical calculations. An experimental formula describing the value of the force transferred from the rail to the railway sleeper on the grounds of the survey site caused by a locomotive was given. Furthermore, the deflection of the chosen railway sleeper due to the generated imperfection was analysed. Finally the objective of the present analysis was to resolve the calculations into the beam element such that the results can be utilised in computational railway practice. In the presented paper also the computational examples, diagrams and tables reflecting influence of analyzed parameters on obtained a CWR track’s displacements are enclosed.

scholarly journals The problems of arising vertical irregularities in operating railway track

2016 ◽  
Vol 2016 (2) ◽  
pp. 9-22 ◽  
Author(s):  
Włodzimierz Andrzej Bednarek
Keyword(s):  
Load Transfer ◽  
Vertical Plane ◽  
Railway Track ◽  
Geometrical Parameters ◽  
Track Structure ◽  
Additional Increase ◽  
Unloaded State ◽  
Ballast Track ◽  
Track Stiffness ◽  
Railway Sleeper

Arising during railway track structure operating the geometrical irregularities of track in vertical plane are the additional sources of interaction between the trains and track. These irregularities have got an unintentional character (arising in random way during track operating, e.g. irregularities in track, change of track geometrical parameters or inhomogeneity of track support) and intentional character (arising e.g. during railway track lifting by VSS plate). The unintentional irregularity causes among other things an additional increase of deflections and stresses in track structure elements, which lead to failures and wear of track elements. Such arising the longitudinal irregularity in track is the reason for various forms of contact between sleeper and ballast. Track stiffness in unloaded state (without forces from trains) causes that the sleepers in various ways rest on the ballast. The analysis of load transfer from wheel by rail to the railway sleeper allows for visualizing the effects of such irregularity for railway track. Furthermore a shape of arising irregularity causes the decrease of train wheel traction efficiency understanding as the degree of its tractive adhesion utilization resulting from static loads. In paper an experimental analysis of arising irregularity in CWR track during its operating is enclosed.

The Specific Characteristics of Shock and Blast Impacts on Construction Sites

2021 ◽  
pp. 81-88
Author(s):  
A.A. Komarov ◽  
Keyword(s):  
Dynamic Load ◽  
Static Load ◽  
Dynamic Loads ◽  
Potential Hazard ◽  
Construction Sites ◽  
Static Loads ◽  
Equivalent Static Loads ◽  
Plane Crash ◽  
Nuclear Plants ◽  
The Impact

The practices of hazardous and unique facilities’ construction imply that specific attention is paid to the issues of safety. Threats associated with crash impacts caused by moving cars or planes are considered. To ensure safety of these construction sites it is required to know the potential dynamic loads and their destructive capacity. This article considers the methodology of reducing dynamic loads associated with impacts caused by moving collapsing solids and blast loads to equivalent static loads. It is demonstrated that practically used methods of reduction of dynamic loads to static loads are based in schematization only of the positive phase of a dynamic load in a triangle forms are not always correct and true. The historical roots of this approach which is not correct nowadays are shown; such approach considered a detonation explosion as a source of dynamic load, including TNT and even a nuclear weapon. Application of the existing practices of reduction of dynamic load to static load for accidental explosions in the atmosphere that occur in deflagration mode with a significant vacuumization phase may cause crucial distortion of predicted loads for the construction sites. This circumstance may become a matter of specific importance at calculations of potential hazard of impacts and explosions in unique units — for instance, in the nuclear plants. The article considers a situation with a plane crash, the building structure load parameters generated at the impact caused by a plane impact and the following deflagration explosion of fuel vapors are determined.

scholarly journals Adaptive Balancing of Robots and Mechatronic Systems

2018 ◽  
Author(s):  
Liviu Ciupitu
Keyword(s):  
Exact Solutions ◽  
Real Time ◽  
Solid Mechanics ◽  
Vertical Plane ◽  
Approximate Solutions ◽  
Real Time Control ◽  
Mechatronic Systems ◽  
Static Loads ◽  
Time Control ◽  
Romanian Academy

Present paper is dealing with the adaptive static balancing of robot or other mechatronic arms that are moving in vertical plane and whose static loads are variable, by using counterweights and springs. Some simple passive and approximate solutions are proposed and an example is shown. The active and exact solutions by using adaptive real time control in the case of unknown variation of static loads are simulated on VIPRO platform developed at Institute of Solid Mechanics of Romanian Academy.

scholarly journals Experimental study on vibration transmissibility of Pre-loaded XPE and PE packaging cushioning material

2021 ◽  
Vol 49 (4) ◽  
pp. 962-968
Author(s):  
Péter Csavajda ◽  
Péter Böröcz
Keyword(s):  
Experimental Study ◽  
Static Load ◽  
Damping Ratio ◽  
Packaging System ◽  
Static Loads ◽  
Resonance Frequencies ◽  
Vibration Transmissibility ◽  
Protective Packaging ◽  
Load Conditions ◽  
Cushioning Material

Most of the shipped products are sensitive against shock and vibration events during the distribution. Various cushioning materials are usually used to prevent the product damages. During the design process the protective packaging system is developed by the engineers based on the cushion and vibration transmissibility features (ie. cushion curve) of the material used. However, after the assembly of the packaged-product, these are stored for various long periods in warehouse. During this time the products pre-load the cushioning material and its parameters can be changed. The main goal of this study is to evaluate the vibration transmissibility of PE and XPE cushioning material at varied storage (pre-loaded) time and static load conditions. Four different kinds of duration (1 hour, 10 hours, 100 hours and 1000 hours) were used for the pre-loading period at three different static loads (3.488 kPa, 4.651 kPa, and 6.976 kPa), and then at 0.5 oct/min sine sweep vibration the peak frequencies of response and vibration transmissibility, and damping ratio were determined. The results show that the effect of pre-loading is minimal by PE material, but can influence the resonance frequencies by XPE cushioning material. The findings of this study help the packaging engineers to understand better the mechanism of these cushioning materials and to design suitable protective packaging systems.

Evaluation of an Innovative Composite Railway Sleeper for a Narrow-Gauge Track under Static Load

2018 ◽  
Vol 22 (2) ◽  
pp. 04017050 ◽  
Author(s):  
Wahid Ferdous ◽  
Allan Manalo ◽  
Gerard Van Erp ◽  
Thiru Aravinthan ◽  
Kazem Ghabraie
Keyword(s):  
Static Load ◽  
Railway Sleeper

scholarly journals Field Investigations on the Effects of Track Lateral Supports on the Ballasted Railway Lateral Resistance

2020 ◽  
Author(s):  
Jabbar Ali Zakeri ◽  
Milad Alizadeh Galdiani ◽  
Seyed Ali Mosayebi
Keyword(s):  
Numerical Modeling ◽  
Bilinear Form ◽  
Field Tests ◽  
New Method ◽  
Railway Track ◽  
Lateral Forces ◽  
Lateral Resistance ◽  
Field Investigations ◽  
Continuous Welded Rail ◽  
Lateral Displacements

Lateral movements of the ballasted railway track especially in the continuous welded rail (CWR) occur in sharp curves because of high lateral forces. Several strategies have been proposed to increase the track lateral resistance which most of them related to track curves with small radii. In this paper, track lateral supports as a new method have been utilized and a series of field tests have been conducted by using the Single Tie Push Tests (STPT) and Multi Tie Push Tests (MTPT) and their results are compared with the numerical modeling. The results of numerical modeling and field tests show that the track lateral resistance significantly increases in the railway with lateral supports, so that the lateral displacements of track are as a bilinear form.

scholarly journals Indicators of the force interaction of the track and rolling stock when a freight car runs on long irregularities, taking into account the action of longitudinal forces

2021 ◽  
Vol 80 (6) ◽  
pp. 359-365
Author(s):  
E. A. Sidorova ◽  
V. O. Pevzner ◽  
A. I. Chechel’nitskiy
Keyword(s):  
Vertical Plane ◽  
Traction Force ◽  
Stability Margin ◽  
Railway Track ◽  
Rolling Stock ◽  
Vertical Force ◽  
Train Operation ◽  
Freight Car ◽  
Dynamics Stability ◽  
Universal Mechanism

Authors describe formation mechanism of long irregularities of the railway track and the importance of their elimination for the track facilities. Based on the results of freight train operation modeling on long irregularities in the traction mode, an analysis of the processes occurring during the motion of heavy trains along a track with such deviations was carried out, modeling was carried out on the basis of the “Universal Mechanism” software package. Based on the results of the calculation, interaction between the track and the rolling stock in the vertical plane was assessed in terms of the magnitude of the vertical force and coeffcients: dynamics, stability margin, Nadal, unloading (in percent) of axle springs of freight car springs. Article analizes the nature of the infuence of the irregularity slope on the decrease in the vertical force transmitted from the wheel to the rail and the change in the traction force on the dynamics of freight cars in the train and passing on long irregularities of the longitudinal profle through the indicators of the vertical force.

Modernization of Railway Track with Composite Sleepers

2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Rakesh Chandmal Sharma ◽  
Srihari Palli ◽  
Sunil Kumar Sharma ◽  
Mritunjoy Roy
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Fibre Composite ◽  
Critical Issue ◽  
Railway Track ◽  
Railway Network ◽  
Railway Sleeper ◽  
Composition Properties

Railway sleeper is an important component of railway network. Its clamping is also a critical issue in order to avoid any slippage and to maintain the alignment or cross level. Earlier, railway network used wooden sleepers worldwide. Further steel sleepers in parallel with wooden sleepers have been employed. Both are replaced with concrete sleepers with the advancements. With the modernization, the idea of railway sleepers with fibre composite materials has been introduced which is accepted worldwide due to its unique features over any other type of sleeper. This paper discuss about different composite material sleepers and review the important features associated with them i.e. composition, properties, advantages and limitations.

scholarly journals Simultaneous Influence of Static Load and Temperature on the Electromechanical Signature of Piezoelectric Elements Bonded to Composite Aeronautic Structures

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Marc Rebillat ◽  
Mikhail Guskov ◽  
Etienne Balmes ◽  
Nazih Mechbal
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Static Load ◽  
Full Range ◽  
Bonding Layer ◽  
Static Loads ◽  
Temperature Variations ◽  
Structural Health ◽  
Piezoelectric Elements ◽  
Simultaneous Influence

Electromechanical (EM) signature techniques have raised a huge interest in the structural health-monitoring community. These methods aim at assessing structural damages and sensors degradation by analyzing the EM responses of piezoelectric components bonded to aeronautic structures. These structures are subjected simultaneously to static loads and temperature variations that affect the metrics commonly used for damage detection and sensor diagnostics. However, the effects of load and temperature on these metrics have mostly been addressed separately. This paper presents experimentations conducted to investigate the simultaneous influence of static load and temperature on these metrics for two kinds of piezoelectric elements (lead zirconate titanate (PZT) and macrofiber composite (MFC)) bonded on sandwich composite materials, for the full range of real-life conditions encountered in aeronautics. Results obtained indicate that both factors affect the metrics in a coupled manner in particular due to the variations of the mechanical properties of the bonding layer when crossing its glass transition temperature. Furthermore, both piezoelectric elements globally behave similarly when subjected to temperature variations and static loads. Simultaneous accounting of both temperature and static load is thus needed in practice in order to design reliable structural health-monitoring systems based on these metrics.

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