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Article

Muzaffer Metin, Arif Ulu, Ozgur Demir and Aytac Arikoglu

In this study, a railway superstructure is modeled with a new approach called locally continuous supporting, and its behavior under the effect of moving load is analyzed…

Abstract

Purpose

In this study, a railway superstructure is modeled with a new approach called locally continuous supporting, and its behavior under the effect of moving load is analyzed by using analytical and numerical techniques. The purpose of the study is to demonstrate the success of the new modeling technique.

Design/methodology/approach

In the railway superstructure, the support zones are not modeled with discrete spring-damping elements. Instead of this, it is considered to be a continuous viscoelastic structure in the local areas. To model this approach, the governing partial differential equations are derived by Hamilton’s principle and spatially discretized by the Galerkin’s method, and the time integration of the resulting ordinary differential equation system is carried out by the Newmark–Beta method.

Findings

Both the proposed model and the solution technique are verified against conventional one-dimensional and three-dimensional finite element models for a specific case, and a very good agreement between the results is observed. The effects of geometric, structural, and loading parameters such as rail-pad length, rail-pad stiffness, rail-pad damping ratio, the gap between rail pads and vehicle speed on the dynamic response of railway superstructure are investigated in detail.

Originality/value

There are mainly two approaches to the modeling of rail pads. The first approach considers them as a single spring-damper connected in parallel located at the centroid of the rail pad. The second one divides the rail pad into several parts, with each of part represented by an equivalent spring-damper system. To obtain realistic results with minimum CPU time for the dynamic response of railway superstructure, the rail pads are modeled as continuous linearly viscoelastic local supports. The mechanical model of viscoelastic material is considered as a spring and damper connected in parallel.

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Article

H. Al Nageim and D. Pountney

The aim is to present findings of a theoretical analysis for optimal design of a concrete trough for a new lightweight low‐profile rail track system.

Abstract

Purpose

The aim is to present findings of a theoretical analysis for optimal design of a concrete trough for a new lightweight low‐profile rail track system.

Design/methodology/approach

A non‐linear numerical optimisation technique is adopted to predict the minimum area of a pre‐tensioned pre‐stressed trough section satisfying the serviceability and ultimate limit states as per British Standard BS 8110 for critical loading and boundary conditions.

Findings

An optimum concrete trough section is calculated to carry all possible load combinations expected during the design life of the track. The performance of the rail, elastomeric pad and track base were found to be satisfactory under the same critical loading and boundary conditions.

Originality/value

The theoretical analysis gives a valuable insight into system parameter values that can optimise design performance and cost. However, these optimal design features now need to be tested experimentally.

Details

Construction Innovation, vol. 7 no. 4
Type: Research Article
ISSN: 1471-4175

Keywords

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Article

FEW people who have witnessed large oil rig structures being loaded and off‐loaded from transporters would think about tribology, but unless the sliding surfaces along…

Abstract

FEW people who have witnessed large oil rig structures being loaded and off‐loaded from transporters would think about tribology, but unless the sliding surfaces along which these tremendously heavy fabrications move are relatively friction‐free, serious difficulties could occur. A similar occasion is at the launching of a new ship from the ship yard when the hull has to travel down the slipways into the sea, and it is important that the hull gets a smooth ride, or it could end up in a damaged state.

Details

Industrial Lubrication and Tribology, vol. 28 no. 2
Type: Research Article
ISSN: 0036-8792

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Article

Matthias Asplund, Stephen Famurewa and Matti Rantatalo

The purpose of this paper is to investigate the failure-driven capacity consumption of wheels on the track, to determine whether there are some relations to vehicle wheel…

Abstract

Purpose

The purpose of this paper is to investigate the failure-driven capacity consumption of wheels on the track, to determine whether there are some relations to vehicle wheel configurations that show a larger amount of failures, and to ascertain the influence of the temperature and the travelling direction of the train on the number of events. This information can be used to develop prognostic health management so that more track capacity can be gained without modifications, re-building or re-investments.

Design/methodology/approach

This paper presents a study of 1,509 warning and alarm events concerning train wheels. The data come from the infrastructure manager's wheel defect detectors and wheel profile measurement system. These data have been analysed and processed to find patterns and connections to different vehicles, travelling directions and temperatures.

Findings

Lower temperatures increase the probability of wheels having high vertical forces. Trains with different wheel configurations show different results. With high vertical forces, the probability of wheel failures at axles 6 and 7 is high for locomotives with two bogies and three axles in each bogie (2×3). All these findings can be used to develop the maintenance, monitoring and inspection principles for wheels.

Practical implications

The inspection of wheels to detect failures needs to be more frequent on days and in seasons with lower temperatures. The wheel inspection should be performed more frequently at axles 6 and 7 for locomotives with a 2×3 wheel configuration. The inspection and monitoring of wheels need to be carried out more carefully for trains travelling south, to avoid a large amount of wheels with high force levels rolling in the southern direction.

Originality/value

The analysis carried out in this paper identifies important factors that correlate with the high occurrence of wheel defects. It also proposes a conceptual e-maintenance model for the combination of wheel condition monitoring data from different system. The value of this study is the provision of information to support prognostic and health management system to support proactive maintenance.

Details

Journal of Quality in Maintenance Engineering, vol. 20 no. 3
Type: Research Article
ISSN: 1355-2511

Keywords

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Article

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 73 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

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Article

John Kountz

Automated material‐handling techniques have been successfully applied in industry for over a decade. The techniques and systems developed to automate warehouse operations…

Abstract

Automated material‐handling techniques have been successfully applied in industry for over a decade. The techniques and systems developed to automate warehouse operations directly apply to libraries. The problem of storing a growing mass of little used but “valuable” materials can be resolved by new material handling strategies, which will also generate improved library services. The characteristics of a miniload automated storage and retrieval system are described, and formulas are presented for calculating the size of system needed by a library. Also included are “rule‐of‐thumb” prices for calculating the approximate costs of a system of a specific size.

Details

Library Hi Tech, vol. 5 no. 4
Type: Research Article
ISSN: 0737-8831

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Article

Guilherme Alencar, Gonçalo Ferreira, Abílio M.P. de Jesus and Rui Calçada

The purpose of this paper is to investigate the fatigue performance of a welded detail from a composite steel-concrete railway twin girder bridge caused by a passenger…

Abstract

Purpose

The purpose of this paper is to investigate the fatigue performance of a welded detail from a composite steel-concrete railway twin girder bridge caused by a passenger train circulating at varying speeds, by identifying the dynamic amplification scenarios induced by resonance. For this purpose, the hotspot stress method is used, instead of the traditional nominal stress methods.

Design/methodology/approach

This paper assesses the fatigue behavior of a welded connection considering critical stress concentration locations (hotspot). Finite element analysis (FEA) is applied, utilizing both a global and a local submodel, made compatible by displacements field interpolation. The dynamic response is obtained through the modal superposition method. Stress cycles are extracted with the rainflow counting method and the fatigue damage is calculated with Palmgren-Miner’s rule. The feasibility of five submodels with different mesh densities, i.e. 1, 2, 4, 8 and 20 mm is verified.

Findings

An increase in the fatigue damage due to the resonance effect was found for the train traveling at a speed of 225 km/h. A good agreement between the computed fatigue damage for the submodels is achieved. However, a non-monotonic hotspot stress/fatigue damage vs mesh density convergence was observed with a peak observed for the 4 mm model, which endorses the mesh sensitivity that could occur when using the surface stress extrapolation detailed rules specified in the standards for the hotspot stress method.

Originality/value

Advanced dynamic analyses are proposed to obtain local stresses in order to apply a local method for the fatigue assessment of a bridge’s structure subjected to high-speed railway traffic on the basis of the mode superposition technique resulting in much less computing times.

Details

International Journal of Structural Integrity, vol. 9 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

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Article

McAlpine Aviation, who operate executive jets, have recently commissioned a new aircraft hangar at Luton Airport. For the approximately 600 sq. metre hangar floor they…

Abstract

McAlpine Aviation, who operate executive jets, have recently commissioned a new aircraft hangar at Luton Airport. For the approximately 600 sq. metre hangar floor they chose Sempol Surfaces F 100 epoxy resin based seamless surface flooring system.

Details

Aircraft Engineering and Aerospace Technology, vol. 58 no. 12
Type: Research Article
ISSN: 0002-2667

Abstract

Details

Anti-Corrosion Methods and Materials, vol. 54 no. 1
Type: Research Article
ISSN: 0003-5599

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Article

Arthur M. Johnston

The exceptional frictional characteristics of PTFE (polytetrafluoroethylene) make it an ideal material for use as a sliding medium when moving heavy loads. Extremely low…

Abstract

The exceptional frictional characteristics of PTFE (polytetrafluoroethylene) make it an ideal material for use as a sliding medium when moving heavy loads. Extremely low friction coefficients can be achieved with pads and slideways made from unfilled PTFE so that massive loads can be moved with relatively small forces. The use of filled grades of PTFE can provide greatly increased wear resistance with a small increase in friction coefficient.

Details

Industrial Lubrication and Tribology, vol. 28 no. 2
Type: Research Article
ISSN: 0036-8792

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