Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 10 of 10

Full-Text Articles in Engineering

Relationship Between Impact Energy And Fracture Toughness Of Prestressed Concrete Railway Sleepers, Sakdirat Kaewunruen, Alexander Remennikov Sep 2009

Relationship Between Impact Energy And Fracture Toughness Of Prestressed Concrete Railway Sleepers, Sakdirat Kaewunruen, Alexander Remennikov

Faculty of Engineering - Papers (Archive)

The prestressed concrete sleepers (or railroad ties), which are installed in railway track systems as the crosstie beam support, are designed to carry and transfer the wheel loads from the rails to the ground. It is well known that railway tracks are subject to impact loading conditions, which are attributable to the train operations with either wheel or rail abnormalities such as flat wheels, dipped rails, etc. These loads are of very high magnitude but short duration. In addition, there exists the potential of repeated load experience during the design life of prestressed concrete sleepers. Prestressed concrete has played a …


Rail Short-Wavelength Irregularity Identification Based On Wheel-Rail Impact Response Measurements And Simulations, Y. Q. Sun, C. Cole, M. Mcclanachan, A. Wilson, S. Kaewunruen, M. B. Kerr Jun 2009

Rail Short-Wavelength Irregularity Identification Based On Wheel-Rail Impact Response Measurements And Simulations, Y. Q. Sun, C. Cole, M. Mcclanachan, A. Wilson, S. Kaewunruen, M. B. Kerr

Faculty of Engineering - Papers (Archive)

Long and short-wavelength dip defects unavoidably exist on railway track top surface. Several manual measurement methods and AK track measurement car were used to measure and to identify these types of defects in a selected track section. The paper considers rail dip irregularities in detail when measured, the dip can be considered as two components. The first one is the large, long dip profile, which can be measured by the survey leveling. The other is a small short dip profile, which is superimposed on the large profile and can be measured using the dip gauge. The corresponding measurement and processed …


State Dependent Properties Of Rail Pads, Sakdirat Kaewunruen, Alexander Remennikov Apr 2009

State Dependent Properties Of Rail Pads, Sakdirat Kaewunruen, Alexander Remennikov

Faculty of Engineering - Papers (Archive)

Rail pad is one of the main components in ballasted railway track systems. It is inserted between the rail and the sleeper to attenuate dynamic wheel/rail interaction forces, preventing the underlying railway track components from excessive stresses. Generally, the dynamic design of tracks relies on the available data, which are mostly focused on the structural condition at a specific toe load. Recent findings show that track irregularities could significantly amplify the loads on railway tracks. This phenomenon gives rise to a concern that the rail pads may experience higher deterioration rate than anticipated in the past. On this ground, an …


Dynamic Properties Of Railway Track And Its Components : A State-Of-The-Art Review, Sakdirat Kaewunruen, Alexander Remennikov Dec 2008

Dynamic Properties Of Railway Track And Its Components : A State-Of-The-Art Review, Sakdirat Kaewunruen, Alexander Remennikov

Faculty of Engineering - Papers (Archive)

Recent findings indicate one of major causes of damages, which is attributed to the resonant behaviours, in a railway track and its components. Basically, when a railway track is excited to generalised dynamic loading, the railway track deforms and then vibrates for certain duration. Dynamic responses of the railway track and its components are the key to evaluate the structural capacity of railway track and its components. If a dynamic loading resonates the railway track’s dynamic responses, its components tend to have the significant damage from excessive dynamic stresses. For example, a rail vibration could lead to defects in rails …


Dynamic Design Guidelines For Prestressed Concrete Sleepers, Alexander Remennikov, Martin H. Murray, Sakdirat Kaewunruen Dec 2008

Dynamic Design Guidelines For Prestressed Concrete Sleepers, Alexander Remennikov, Martin H. Murray, Sakdirat Kaewunruen

Faculty of Engineering - Papers (Archive)

Current design philosophy, outlined in AS 1085.14, is based on the analysis of permissible stresses resulting from quasi-static wheel loads and essentially the static response of concrete sleepers. In general, cracking can incur when the bottom fibre stress is larger than tensile strength of concrete. Premature cracking of prestressed concrete sleepers has been detected in railway tracks. The major cause of cracking is the infrequent but high-magnitude wheel loads produced by a small percentage of “out-of-round” wheels or railhead surface defects, which are crudely accounted for in AS 1085.14 by a single load factor. Based on the current design method, …


Dynamic Responses Of Marine Risers/Pipes Transporting Fluid Subject To Top End Excitations, J. Leklong, S. Chucheepsakul, S. Kaewunruen Nov 2008

Dynamic Responses Of Marine Risers/Pipes Transporting Fluid Subject To Top End Excitations, J. Leklong, S. Chucheepsakul, S. Kaewunruen

Faculty of Engineering - Papers (Archive)

This paper deals with the dynamic responses to top end excitation of marine risers/pipes conveying internal fluid. The marine riser is often used as a flexible link between undersea bore head and subsurface offshore platform. The tidal waves and the changes of sea level consistently excite its top end connected to a floating vessel. In order to carry out the performance-based design of the marine risers, the evaluation of their dynamic responses to top end excitations is imperative. In this study, the marine riser is simulated using twodimensional beam elements. Energy functional of the marine risers conveying fluids is derived …


Influence Of Joint Stiffness On The Free Vibrations Of A Marine Riser Conveying Fluid, S. Kaewunruen, T. Mccarthy, J. Leklong, S. Chucheepsakul Nov 2008

Influence Of Joint Stiffness On The Free Vibrations Of A Marine Riser Conveying Fluid, S. Kaewunruen, T. Mccarthy, J. Leklong, S. Chucheepsakul

Faculty of Engineering - Papers (Archive)

The marine risers are generally used as the main transport means for economic materials and resources discovered undersea. In general, the marine risers are secured at either an offshore platform or a vessel. Both ends of the riser are to be adjusted to obey with the design criteria but in many cases their rotational stiffness is hardly set free for the hinge connection. This paper integrates the analytical investigation and the design consideration for the effects of end supports on the free vibrations of a marine riser conveying fluid. It is well known that resonances of marine risers/pipes can cause …


Strategic Approaches For Management Of Risk In Geomechanics, R. Chowdhury, P. Flentje Oct 2008

Strategic Approaches For Management Of Risk In Geomechanics, R. Chowdhury, P. Flentje

Faculty of Engineering - Papers (Archive)

This paper outlines the challenges facing geomechanics and advocates some strategies for dealing with these challenges. Advancement of geomechanics and its application in the past may be seen in a historical context as serving the needs of society such as the development of infrastructure and natural resources. The needs of society are changing rapidly due to population growth, increasing urbanisation and globalisation. Climate change poses specially challenges, the impacts increasing with time. Therefore, development of new strategies is essential. For example, greater attention should be given to the development of interdisciplinary approaches. It is vitally important that systematic methods be …


Impact Damage Classification Of Railway Prestressed Concrete Sleepers, Sakdirat Kaewunruen, Alexander Remennikov Sep 2008

Impact Damage Classification Of Railway Prestressed Concrete Sleepers, Sakdirat Kaewunruen, Alexander Remennikov

Faculty of Engineering - Papers (Archive)

Commonly, railway tracks suffer with the extreme loading conditions, which are attributed to the train operations with either wheel or rail abnormalities such as flat wheels, dipped rails, etc. These loads are of very high magnitude but short duration, as well as they are of low-possibility occurrence during the design life of the prestressed concrete sleepers. In spite of the most common use of the prestressed concrete sleepers in railway tracks, their impact responses and behaviours are not deeply appreciated nor taken into the design consideration. Up until recently, a new limit states design approach, whereas the dynamic effects are …


Reliability Assessment Of Railway Prestressed Concrete Sleepers, Sakdirat Kaewunruen, Alexander Remennikov Jun 2008

Reliability Assessment Of Railway Prestressed Concrete Sleepers, Sakdirat Kaewunruen, Alexander Remennikov

Faculty of Engineering - Papers (Archive)

This paper carries out the assessment of reliability indices of railway prestressed concrete sleepers designed in accordance with Australian Standard: AS1085.19. The current design approach of the prestressed concrete sleeper relies on the permissible stresses over crosssectional area. Loading condition acting on railway sleepers is considered from axle burden and dynamic amplification factor. On the basis of Australian design of railway prestressed concrete sleepers, only service limit states are considered; however, the design challenge is to provide adequate resistance of certain cross sections to both positive and negative bending moments. In this paper, the service limit states functions are formulated …