@article{ author = {Ataei, S. and miri, A. and Jahangiri, M.}, title = {Deflection Measurement of Masonry Arch Bridges with Tall Piers: Case Study of Shahbazan Bridge}, abstract ={A common practice for detailed assessment of masonry bridges is to use recorded deflection signature of mid-span of such structures due to predefined loading schemes. However, measuring the deflection of bridges with tall piers or those situated over deep valleys introduces certain difficulties, since common deflection-meters require a reference point relative to which the measurement is carried out. Common approaches currently proposed by researchers include indirect measurement of deflection based on acceleration or tilt measurements. However, due to small values of deflection in masonry arch bridges, such approaches may not produce the expected results. Moreover, optical methods are difficult and rather expensive to implement due to small deflection values and far reaching points. This paper proposes the application of piers as the reference point of common deflection meters. To demonstrate the applicability of the proposed approach, a case study is carried out in which a 70 years old railway masonry arch bridge is instrumented for structural health monitoring. The studied bridge is a seven span railway masonry arch bridge with tall piers of almost 40 meters and span lengths of 21.5m. It is concluded that vertical deflection signature of conventional method could be derived from inflating that of proposed method by a factor of 1.86. Therefore, the method proves to be practical for the purpose of structural health monitoring and calibration of numerical models.}, Keywords = {Health monitoring Masonry arch bridge Dynamic load tests Deflection-meters}, volume = {3}, Number = {1}, pages = {1-8}, publisher = {Iran University of Science & Technology}, doi = {10.22068/IJRARE.3.1.1}, url = {http://ijrare.iust.ac.ir/article-1-91-en.html}, eprint = {http://ijrare.iust.ac.ir/article-1-91-en.pdf}, journal = {International Journal of Railway Research}, issn = {2423-3838}, eissn = {2423-382X}, year = {2016} } @article{ author = {Tamannaei, M. and Shafiepour, M. and Haghshenas, H. and Tahmasebi, B.}, title = {Two Comprehensive Strategies to Prioritize the Capacity Improvement Solutions in Railway Networks (Case Study: Iran)}, abstract ={The aim of this study is to present two comprehensive strategies for prioritizing the capacity improvement solutions in the railway networks. The solutions considered in this study include: promoting to double-track railways, block signaling system, electrification and re-opening the closed stations. The first strategy is based on a local approach, which concentrates on the critical block sections individually; whereas the second one is based on a global approach, for which the solutions are executed according to the load flow of the network and the capability of the demand absorption after removing the bottlenecks emerged in the specific corridors. For both strategies, the value of the absorbed excessive demand, the benefits, the costs, and the net present value (NPV) indicator are employed to compare the solutions. To evaluate the proposed strategies, Iranian railway network was examined. The results demonstrate the excellence of the second strategy, rather than the first one. By executing the first and the second strategies, 45.6 and 52.52 million tons per year, of the total potential demand can be absorbed to the network, respectively. The NPV values were 5.78 and 7.81 billion dollars for the first and the second strategies, respectively. In spite of more investments required, the second strategy is more efficient, rather than the first one.}, Keywords = {Capacity bottleneck Railway network Capacity based assignment Capacity improvement solutions Potential demand}, volume = {3}, Number = {1}, pages = {9-18}, publisher = {Iran University of Science & Technology}, doi = {10.22068/IJRARE.3.1.9}, url = {http://ijrare.iust.ac.ir/article-1-92-en.html}, eprint = {http://ijrare.iust.ac.ir/article-1-92-en.pdf}, journal = {International Journal of Railway Research}, issn = {2423-3838}, eissn = {2423-382X}, year = {2016} } @article{ author = {Fazel, S. S. and JafariKaleybar, H. and MadadiKojabadi, H.}, title = {An Efficient Strategy for Power Rating Reduction of Back-to-Back Converters Used in Railway Power Conditioner}, abstract ={One of the most common solutions to deal with the power quality issues of electrical railway systems is employing Railway Power Conditioner (RPC). In the conventional mode of operation, the RPC power rating deployed in every Traction Power Substation (TPS) is significantly large. This paper mainly focuses on the power rating reduction of RPC through presenting a novel combinatorial compensation method. The inductive and capacitive switching algorithm retrieved from Steinmetz circuit lead to additional auxiliary balance in sequential TPS which declines the RPC function in elimination of the Negative Sequence Current (NSC). The proposed method can reduce the voltage over Sectioning Posts (SP), DC-link operation voltage, back-to-back (B2B) converters rating and installation costs. The accuracy and effectiveness of the proposed strategy are confirmed via simulation results obtained by MATLAB/SIMULINK program.}, Keywords = {Railway power conditioner Power rating Back to back converter power quality}, volume = {3}, Number = {1}, pages = {19-28}, publisher = {Iran University of Science & Technology}, doi = {10.22068/IJRARE.3.1.19}, url = {http://ijrare.iust.ac.ir/article-1-93-en.html}, eprint = {http://ijrare.iust.ac.ir/article-1-93-en.pdf}, journal = {International Journal of Railway Research}, issn = {2423-3838}, eissn = {2423-382X}, year = {2016} } @article{ author = {Rahmati, A. and Sharavi, M.}, title = {Volume-Filling Effects on Sloshing Frequency in Simplified and Explicit Dynamic Finite Element Models of Tank Wagons During Braking and Turning}, abstract ={Numerical analysis of fluid sloshing in tank wagons is amongst essential research ideas that are focused by railway engineers. The free surface of fluid becomes unstable and turns into a dynamic complex non-linear problem for fluid-structure interaction (FSI). In this paper, initially, the dynamic response of the tank, including lateral force analysis and pressure distribution during braking, is obtained by using an explicit dynamic finite element model based on the Multi Material Arbitrary Lagrangian Eulerian method (MM-ALE). Then, the simplified model is developed for sloshing during turning. Numerical finite element model is validated using a test setup. Comparing these models during turning with parametric studies for tank filling, it is observed that the estimated frequency and amplitude of sloshing, when filling is less than 25%, are less than 10% different form the measured results. Therefore, the simplified model in the above conditions can be used with an acceptable degree of accuracy. It also causes a remarkable reduction in the time and the cost of the numerical calculations}, Keywords = {}, volume = {3}, Number = {1}, pages = {29-36}, publisher = {Iran University of Science & Technology}, doi = {10.22068/IJRARE.3.1.29}, url = {http://ijrare.iust.ac.ir/article-1-94-en.html}, eprint = {http://ijrare.iust.ac.ir/article-1-94-en.pdf}, journal = {International Journal of Railway Research}, issn = {2423-3838}, eissn = {2423-382X}, year = {2016} } @article{ author = {HadjMabrouk, H.}, title = {Knowledge Based System for the Evaluation of Safety and the Prevention of Railway Accidents}, abstract ={This paper describes a contribution to improving the usual safety analysis methods used in the certification of railway transport systems. The methodology is based on the complementary and simultaneous use of knowledge acquisition and machine learning. The purpose is contributed to the generation of new accident scenarios that could help experts to conclude on the safe character of a new rail transport system. The method of analysis and evaluation is centered on the summarized failures (SFs) which are involved in accident scenarios capitalized. A summarized failure (SF) is a generic failure produced by the combination of a set of basic failures which has the same effect on the performance of the system. Each scenario brings into play one or more SFs. The purpose is to automatically generate a recognition function for each SF associated with a scenario class. The SF recognition function is a production rule which establishes a link between a set of facts (parameters which describe a scenario or descriptors) and the SF fact. A base of evaluation rules can be generated for each class of scenarios. The SF deduction stage requires a preliminary phase during which the rules which have been generated are transferred to an expert system in order to construct a scenario evaluation knowledge base. The evaluation knowledge base is exploited by forward chaining by an inference engine and generates the summarized failures (SFs) which must enter into the description of the scenario which is to be evaluated.}, Keywords = {}, volume = {3}, Number = {1}, pages = {37-44}, publisher = {Iran University of Science & Technology}, doi = {10.22068/IJRARE.3.1.37}, url = {http://ijrare.iust.ac.ir/article-1-107-en.html}, eprint = {http://ijrare.iust.ac.ir/article-1-107-en.pdf}, journal = {International Journal of Railway Research}, issn = {2423-3838}, eissn = {2423-382X}, year = {2016} } @article{ author = {Molatefi, H. and Azizi, M. and Mozafari, H.}, title = {Crashworthiness Analysis and Energy Absorption Enhancement of a Passenger Rail Vehicle}, abstract ={Interests in increasing the trains’ speed of travel, generated higher degrees of wariness about the possible sever accidents. Since, the passenger wagon car body needs to be a safe compartment for its occupants therefore; great attention should be paid on its design.  In this study, a passenger car body that is originally made in Eastern Germany and its chassis are modeled to simulate the crash analysis according to EN 15227 standard. The results are then used in order to optimize the wagon chassis design. This investigation is performed in two steps. In the first step, which consists of simulation of the original wagon model, it is found that due to the lack of efficiency in crash force absorbent, some modifications in the design are needed. In the second step, the original chassis is modified and by implementing honeycomb cores as energy absorbing devices, higher energy absorption is achieved. Furthermore, impact stresses in mid-section of the chassis considerably decreased. The proposed energy absorbing device can be implemented in the front end of the chassis to provide a crashworthy structure. The results show that by modifying the under-frame the amount of energy absorption is increased by 46%, and also, the amount of maximum stress in the center of the under-frame isreduced by 66%}, Keywords = {}, volume = {3}, Number = {1}, pages = {45-54}, publisher = {Iran University of Science & Technology}, doi = {10.22068/IJRARE.3.1.45}, url = {http://ijrare.iust.ac.ir/article-1-106-en.html}, eprint = {http://ijrare.iust.ac.ir/article-1-106-en.pdf}, journal = {International Journal of Railway Research}, issn = {2423-3838}, eissn = {2423-382X}, year = {2016} } @article{ author = {Biabani, M. Mahdi and Indraratna, Buddhima and Nimbalkar, Sanjay}, title = {Improved Performance of Subballast Stabilized Using Geocell for High Speed Train}, abstract ={Rapid urbanization and growing industrial demand in many developing countries has led to frequent congestion of the transport infrastructure. Therefore, the expansion of high-speed rail (HSR) networks is crucial to meet this growing demand. Nevertheless, applying high cyclic stress causes significant lateral spreading and in turn excessive settlements of the track substructure. This problem becomes more crucial when the subballast layer is constructed using locally available poor quality granular material in order to keep the construction costs to minimum. The use of planar form of geosynthetics (geogrid, geotextile, geocomposite) to improve the performance of rail track is well established. Large-scale laboratory and full scale field studies conducted in the past at the Center for Geomechanics and Railway Engineering (CGRE) of the University of Wollongong, NSW, Australia, have shown that geogrids and geocomposites of appropriate technical specifications can effectively reduce track settlement. Recent studies have shown that cellular confinement, known as geocell mattress, can offer more confinement than planar geogrid for the infill material. By employing geocell as reinforcement in subballast layer, tensile strength mobilized as an additional confinement and arrests lateral spreading of infill material and help to maintain track geometry.}, Keywords = {Subballast, Geocell reinforcement, Additional confining pressure, Cyclic loading}, volume = {3}, Number = {2}, pages = {1-8}, publisher = {Iran University of Science & Technology}, doi = {10.22068/IJRARE.3.2.1}, url = {http://ijrare.iust.ac.ir/article-1-166-en.html}, eprint = {http://ijrare.iust.ac.ir/article-1-166-en.pdf}, journal = {International Journal of Railway Research}, issn = {2423-3838}, eissn = {2423-382X}, year = {2016} } @article{ author = {Naeimi, Meysam and Li, Zili and Dollevoet, Rolf}, title = {Preliminary Results on Dynamic Analysis of a New Test Rig for Wheel-Rail Contact Studies}, abstract ={A new reduced–scale test rig is developed owing to significantly contribute to the applicability of the laboratory tests on rolling contact fatigue (RCF) in wheel-rail material. This paper introduces the dynamic analysis of the test rig, in order to assess the vibration behaviour of the system with respect to contact phenomenon. Finite element modelling (FEM) is used to simulate the mechanical behaviour of the test rig, representing dynamic response of the components under wheel impact loading conditions. To study the influence of scaling on the new rig, and to understand the functional relationships between the mechanical parameters, two tentative scales i.e. 1/5 and 1/7 are defined as global scale factors of the rig. FE models of the scaled test rig together with a model of actual-size railway system are analysed and their dynamic characteristics are compared. Based on results of dynamic simulations, a strong evidence of association between the chosen scale factors and dominant frequencies of vibrations was found. The major dynamic parameters of the new test rig are lastly derived based on the numerical investigations.}, Keywords = {New test rig, dynamic behaviour, scale, finite element method}, volume = {3}, Number = {2}, pages = {9-19}, publisher = {Iran University of Science & Technology}, doi = {10.22068/IJRARE.3.2.9}, url = {http://ijrare.iust.ac.ir/article-1-147-en.html}, eprint = {http://ijrare.iust.ac.ir/article-1-147-en.pdf}, journal = {International Journal of Railway Research}, issn = {2423-3838}, eissn = {2423-382X}, year = {2016} } @article{ author = {Zargaran, Amin and Soltanpour, Mehdi and Rajabpour, Ali}, title = {Optimization of Fan Geometry for Urban Train Traction Motors using Coupled Numerical Electromagnetic and Thermal Analysis}, abstract ={One of the most important parameters in designing electrical motors is heat generation by the motor and the way it is dissipated. Temperature rising reduce efficiency and reliability of traction motors and leads to failure. In this paper, an urban train traction motor in a 3D computational fluid dynamics (CFD) simulation has been investigated. Maxwell software for electromagnetic simulation and ANSYS Fluent for thermal simulation have been used. In the discussed motor, air is blown directly from atmosphere into the motor by embedded inlets and discharged to the atmosphere after passing through the motor components and fan. Heat generation rate has been derived from electromagnetic simulation results. At first step, the validity of the simulation results is evaluated by comparing the temperature distribution of motor using reference fan with the thermal requirements of the working class. Afterward, for two different blade geometries and different number of blades are. In the following, the optimized fan geometry is obtained by comparing the fan performance in each case.}, Keywords = {Heat generation, Train traction motor, Computational fluid dynamics}, volume = {3}, Number = {2}, pages = {21-28}, publisher = {Iran University of Science & Technology}, doi = {10.22068/IJRARE.3.2.21}, url = {http://ijrare.iust.ac.ir/article-1-175-en.html}, eprint = {http://ijrare.iust.ac.ir/article-1-175-en.pdf}, journal = {International Journal of Railway Research}, issn = {2423-3838}, eissn = {2423-382X}, year = {2016} } @article{ author = {Akbari, S and Rosami, z and Khoshharf, A and Fazel, SS}, title = {Applying Frequency Response Method for Contact Rails Fault Diagnosing in Ungrounded Electrical Railway System}, abstract ={Abstract General faults in regular electrical railways system could be detect by implementing the specific protection functions such as ground fault or sensitive earth fault. Otherwise, in ungrounded electrical railway systems which using both feeding and return contact rail at the same time, fault detection cannot done with above-mentioned function. Due to recent growth in electrical railway network especially in metropolises, it is an essential requirement to improve operation and safety indexes by using efficient fault preventing and fault clearing method in minimum time. In this applied research, a new fault diagnosing method developed by using frequency response of contact rails system. This technique based on observing pattern changes caused by expected faults such as broken contact rail, contact rail to ground faults on feed or return circuit frequency response.  }, Keywords = {frequency response, contact rails, fault, ungrounded electrical railways}, volume = {3}, Number = {2}, pages = {29-38}, publisher = {Iran University of Science & Technology}, doi = {10.22068/IJRARE.3.2.29}, url = {http://ijrare.iust.ac.ir/article-1-143-en.html}, eprint = {http://ijrare.iust.ac.ir/article-1-143-en.pdf}, journal = {International Journal of Railway Research}, issn = {2423-3838}, eissn = {2423-382X}, year = {2016} } @article{ author = {Ahadi, Hamid Reza and Rashed, Farnoosh}, title = {Performance Evaluation of Tehran Subway Stations}, abstract ={Efficiency evaluation is one of the major issues in urban transportation. Since the efficiency of the systems is affected by its data and output, what makes the results of the performance evaluation valid and applicable, is selecting the appropriate data and outputs of the system. In this study, the efficiency of the subway stations in Tehran in case of return, compared to the fixed scale, is measured and ranked in a three-year period (2010-2012), by using data envelopment analysis (DEA)[1]; that is a non-parametric method for assessing the performance of the units (DMUs)[2]. Also In this study, by the analysis of the sensitivity of the model, compared to the inputs, their impact on the performance of the stations is examined. The results suggest that, stations of Sadeghiyeh, Shar-e-Rey and Panzdah-e-Khordad, have the highest level of performance and can be used as a proper model for inefficient stations  }, Keywords = {Tehran Metro, performance evaluation, data envelopment analysis}, volume = {3}, Number = {2}, pages = {39-46}, publisher = {Iran University of Science & Technology}, doi = {10.22068/IJRARE.3.2.39}, url = {http://ijrare.iust.ac.ir/article-1-144-en.html}, eprint = {http://ijrare.iust.ac.ir/article-1-144-en.pdf}, journal = {International Journal of Railway Research}, issn = {2423-3838}, eissn = {2423-382X}, year = {2016} } @article{ author = {Demir, Abdullah}, title = {Static Analysis of Railway Overheads Considering Pantograph Effect}, abstract ={This article is concerned with the static analysis of structural cables used in railway overheads. Structural analysis computer program named ANSYS is used for analysis. Two effects are considered in the analysis. First one is the bending behavior effect of cables. BEAM188 in addition to LINK10 and LINK180 is used to see the difference in case of additional bending effect. Besides, LINK10 and LINK180 is also compared. Second one is the effect of pantograph. Pantograph is modelled as a contact element instead of a force. Accordingly, some sample cable systems similar to railway overhead are analyzed.  }, Keywords = {railway overheads, structural cable, sliding contacts, nonlinear analysis}, volume = {3}, Number = {2}, pages = {47-56}, publisher = {Iran University of Science & Technology}, doi = {10.22068/IJRARE.3.2.47}, url = {http://ijrare.iust.ac.ir/article-1-145-en.html}, eprint = {http://ijrare.iust.ac.ir/article-1-145-en.pdf}, journal = {International Journal of Railway Research}, issn = {2423-3838}, eissn = {2423-382X}, year = {2016} }