Comments on Vibration of simply supported beams under a single moving load: A detailed study of cancellation phenomenon by C.P. Sudheesh Kumar, C.Sujatha, K.Shankar [Int.J.Mech.Sci.99(2015) 40 47,doi:10.1016/j.ijmecsci.2015.05.001]

Museros Romero, P.; Moliner, E. (2017). Comments on Vibration of simply supported beams under a single moving load: A detailed study of cancellation phenomenon by C.P. Sudheesh Kumar, C.Sujatha, K.Shankar [Int.J.Mech.Sci.99(2015) 40 47,doi:10.1016/j.ijmecsci.2015.05.001]. International Journal of Mechanical Sciences. 128-129:709-713. doi:10.1016/j.ijmecsci.2016.07.005S709713128-12

Mejora del comportamiento dinámico de puentes de ferrocarril mediante reaccionamiento con amortiguadores fluido-viscosos

This research work is devoted to the problem of excessive vertical vibrations that short to medium-span railway bridges may experiment due to resonance phenomena. A new alternative based on externally increasing the overall damping of the structure by retrofitting the deck with fluid-viscous dampers is proposed in order to reduce detrimental levels of transverse acceleration to admissible ones. This solution could substitute a classical strengthening process or even the complete demolition and replacement of the deck in existing structures under new traffic requirements such as an increase in the speed of the line. A particular configuration of the retrofitting system is proposed which allows the transformation of the vertical oscillations that the deck experiments under the circulation of the railway vehicles into elongation rates of the devices, leading to energy dissipation and the subsequent reduction of the super-structure resonant response. The proposed system could be installed in the original structure and maintained without interfering with everyday traffic

Advances in the analysis of short span railway bridges for high-speed lines

The physical model based on moving constant loads is widely used for the analysis of railway bridges. Nevertheless, the moving loads model is not well suited for the study of short bridges (L⩽20–25 m) since the results it produces (displacements and accelerations) are much greater than those obtained from more sophisticated ones. In this paper two factors are analysed which are believed to have an influence in the dynamic behaviour of short bridges. These two factors are not accounted for by the moving loads model and are the following: the distribution of the loads due to the presence of the sleepers and ballast layer, and the train–bridge interaction. In order to decide on their influence several numerical simulations have been performed. The results are presented and discussed herein

Retrofit of existing railway bridges of short to medium spans for high-speed traffic using viscoelastic dampers

This paper presents a study on the energy-absorbing capacities of viscoelastic dampers (VEDs) for reducing the resonant vibrations of simply supported high-speed railway bridges of short to medium span. The proposed solution is based on retrofitting the bridge with a set of discrete VEDs connected to the slab and to an auxiliary structure, placed underneath the bridge deck and resting on the abutments. In this investigation attention is focused on mitigating flexural vibrations; therefore, both the bridge and the auxiliary structure are modelled as simply supported beams with Bernoulli-Euler (B-E) behavior, whereas a discrete fractional derivative model simulates the behavior of the damping material. Firstly, a parametric study of this planar model is carried out, which has led to a dimensioning procedure of the dissipative system. The technical feasibility of this particular retrofit design is numerically evaluated by applying it to a numerical model of a simply supported railway bridge with inadmissible vertical accelerations. Numerical results show that the dynamic response of the structure can be significantly reduced in resonance with the proposed damping system. © 2012 Elsevier Ltd.The authors wish to express their gratitude to the Spanish Ministry of Public Works for the financial support received in the framework of Research Project number 80021/A04.Moliner Cabedo, E.; Museros Romero, P.; Martínez Rodrigo, MDLD. (2012). Retrofit of existing railway bridges of short to medium spans for high-speed traffic using viscoelastic dampers. Engineering Structures. 40:519-528. doi:10.1016/j.engstruct.2012.03.016S5195284

RETROFIT OF EXISTING RAILWAY BRIDGES OF SHOR TO MEDIUM SPANS FOR HIGH-SPEED TRAFFIC USING VISCOELASTIC DAMPERS

Elsevier Moliner Cabedo, E.; Museros Romero, P.; Martínez Rodrigo, MDLD. (2012). Retrofit of existing railway bridges of short to medium spans for high-speed traffic using viscoelastic dampers. Engineering Structures. 40:519-528. doi:10.1016Structures. 40:519-528. doi:10. /j.engstruct.2012 Abstract. This paper presents a study on the energy-absorbing capacities of viscoelastic dampers (VEDs) for reducing the resonant vibrations of simply supported high-speed railway bridges of short to medium span. The proposed solution is based on retrofitting the bridge with a set of discrete VEDs connected to the slab and to an auxiliary structure, placed underneath the bridge deck and resting on the abutments. In this investigation attention is focused on mitigating flexural vibrations; therefore, both the bridge and the auxiliary structure are modelled as simply supported beams with Bernoulli−Euler (B-E) behavior, whereas a discrete fractional derivative model simulates the behavior of the damping material. Firstly, a parametric study of this planar model is carried out, which has led to a dimensioning procedure of the dissipative system. The technical feasibility of this particular retrofit design is numerically evaluated by applying it to a numerical model of a simply supported railway bridge with inadmissible vertical accelerations. Numerical results show that the dynamic response of the structure can be significantly reduced in resonance with the proposed damping system.

Measures of Similarity Between Objects Based on Qualitative Shape Descriptions

A computational approach for comparing qualitative shape descriptions (QSDs) of objects within digital images is presented. First, the dissimilarity of qualitative features of shape is measured: (i) intuitively using conceptual neighbourhood diagrams; and (ii) mathematically using interval distances. Then, a similarity measure between QSDs is defined and tested using images of different categories of the MPEG-7-CE-Shape-1 library, images of tiles used to build mosaics, and a collection of Clipart images. The results obtained show the effectiveness of the similarity measure defined, which is invariant to translations, rotations and scaling, and which implicitly manages deformation of shape parts and incompleteness

Study of Vibrations in a Short-Span Bridge Under Resonance Conditions Considering Train-Track Interaction

[EN] Resonance is a phenomenon of utmost importance in railways engineering, leading to vast damages both in track and vehicles. A short-span bridge has been modeled by means of a finite elements method model, calibrated and validated with real data, to study resonance vibrations induced by the passage of trains. Furthermore, the influence of vehicle speed and track damping on the vibrations registered on the rail, the sleeper and the bridge has been assessed. Different track and vehicle pathologies have been proposed and their effect on the resonance of the bridge has been evaluated.Ribes-Llario, F.; Velarte-González, JL.; Pérez-Garnes, JL.; Real Herráiz, JI. (2016). Study of Vibrations in a Short-Span Bridge Under Resonance Conditions Considering Train-Track Interaction. Latin American Journal of Solids and Structures. 13(7):1236-1249. doi:10.1590/1679-78252773S12361249137Ahlström, J., & Karlsson, B. (1999). Microstructural evaluation and interpretation of the mechanically and thermally affected zone under railway wheel flats. Wear, 232(1), 1-14. doi:10.1016/s0043-1648(99)00166-0Bian, X., Chao, C., Jin, W., & Chen, Y. (2011). A 2.5D finite element approach for predicting ground vibrations generated by vertical track irregularities. Journal of Zhejiang University-SCIENCE A, 12(12), 885-894. doi:10.1631/jzus.a11gt012Grassie, S. L., & Kalousek, J. (1993). Rail Corrugation: Characteristics, Causes and Treatments. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 207(1), 57-68. doi:10.1243/pime_proc_1993_207_227_02Gupta, A., & Singh Ahuja, A. (2014). Dynamic Analysis of Railway Bridges under High Speed Trains. Universal Journal of Mechanical Engineering, 2(6), 199-204. doi:10.13189/ujme.2014.020604Ju, S. H., & Lin, H. T. (2003). Resonance characteristics of high-speed trains passing simply supported bridges. Journal of Sound and Vibration, 267(5), 1127-1141. doi:10.1016/s0022-460x(02)01463-3Kwark, J. W., Choi, E. S., Kim, Y. J., Kim, B. S., & Kim, S. I. (2004). Dynamic behavior of two-span continuous concrete bridges under moving high-speed train. Computers & Structures, 82(4-5), 463-474. doi:10.1016/s0045-7949(03)00054-3Lu, Y., Mao, L., & Woodward, P. (2012). Frequency characteristics of railway bridge response to moving trains with consideration of train mass. Engineering Structures, 42, 9-22. doi:10.1016/j.engstruct.2012.04.007Makino, T., Yamamoto, M., & Fujimura, T. (2002). Effect of material on spalling properties of railroad wheels. Wear, 253(1-2), 284-290. doi:10.1016/s0043-1648(02)00117-5Mao, L., & Lu, Y. (2013). Critical Speed and Resonance Criteria of Railway Bridge Response to Moving Trains. Journal of Bridge Engineering, 18(2), 131-141. doi:10.1061/(asce)be.1943-5592.0000336Museros, P., Romero, M. ., Poy, A., & Alarcón, E. (2002). Advances in the analysis of short span railway bridges for high-speed lines. Computers & Structures, 80(27-30), 2121-2132. doi:10.1016/s0045-7949(02)00261-4Pal, S., Valente, C., Daniel, W., & Farjoo, M. (2012). Metallurgical and physical understanding of rail squat initiation and propagation. Wear, 284-285, 30-42. doi:10.1016/j.wear.2012.02.013Sheng, X., Jones, C. J. C., & Thompson, D. J. (2004). A theoretical model for ground vibration from trains generated by vertical track irregularities. Journal of Sound and Vibration, 272(3-5), 937-965. doi:10.1016/s0022-460x(03)00782-xSimon, S., Saulot, A., Dayot, C., Quost, X., & Berthier, Y. (2013). Tribological characterization of rail squat defects. Wear, 297(1-2), 926-942. doi:10.1016/j.wear.2012.11.011Wang, Y., Wei, Q., Shi, J., & Long, X. (2010). Resonance characteristics of two-span continuous beam under moving high speed trains. Latin American Journal of Solids and Structures, 7(2), 185-199. doi:10.1590/s1679-78252010000200005Xia, H., Zhang, N., & Guo, W. W. (2006). Analysis of resonance mechanism and conditions of train–bridge system. Journal of Sound and Vibration, 297(3-5), 810-822. doi:10.1016/j.jsv.2006.04.022Yang, Y. B., & Lin, C. W. (2005). Vehicle–bridge interaction dynamics and potential applications. Journal of Sound and Vibration, 284(1-2), 205-226. doi:10.1016/j.jsv.2004.06.03

High-speed trains derived from Annex E / EN 1991-2

This new version of dataset "doi: 10.17632/hdr6dd5xv2.1" is intended to fix an error detected in the definition of the "conventional trains" contained in such previous dataset. The error arising from a bug in a computer code, was detected in Feb 2023. Therefore, while in the present version the conventional trains have been updated, the "articulated" and "regular" ones remain unchanged.The dataset contains 3759 realizations of axle load sequences corresponding to potential high-speed trains (conventional, articulated, regular) which comply with the prescriptions in Annex E / Eurocode EN 1991-2, Actions on structures - Part 2: Traffic loads on bridges. Therefore, the dataset describes potential sources of dynamic excitation for bridges, falling within the range of application of EN 1991-2 for high-speed lines.Annex E in EN 1991-2 establishes the conditions that a sequence of train loads ought to fulfil to respect the limits of validity of load model HSLM-A. Consequently, this dataset represents a (dense) ensemble of trains defined under the range of validity currently associated to HLSM-A. Such conditions are described in the attached “Characteristics of the high-speed trains derived from Annex E (EN1991-2).pdf”. Four types of traction are considered: (1) distributed traction (this one not used for regular trains); (2) power cars with wheelbases equal to HSLM-A; (3) power cars with wheelbases equal to RENFE S103 (a Siemens unit); (4) power cars with wheelbases equal to RENFE S112 (Talgo Avril).One condition stipulated in Annex E / EN 1991-2 is not respected in this dataset: the requirement that wheelbase ratios D/dBA and (dBS-dBA)/dBA should not be close to integers. This deliberate omission is assumed following publications where it is demonstrated that the vibratory effects produced by these integer wheelbase ratios are not significantly larger than the effects from other ratios far from being integer. Indeed, a number of current high-speed vehicles feature integer or near-integer wheelbase ratios, as reported in [3] below (references follow): [1] P. Museros et al. Dynamic behaviour of bridges under critical articulated trains: Signature and bogie factor applied to the review of some regulations included in EN 1991-2. PI Mech Eng F-J Rai, 2021; 235(5):655-675; [2] P. Museros et al. Dynamic effect of trains with articulated coaches and Jacobs bogies with integer wheelbase ratios. XI Int Conf on Struc Dyn EURODYN 2020; 2646-2657; [3] P. Museros et al. Dynamic behaviour of bridges under critical conventional and regular trains: review of some regulations included in EN 1991-2. PI Mech Eng F-J Rai, 2022 (submitted).When the HSLM-A model was devised, its creators envisaged that certain types of potential vehicles ought to be considered in designing railway bridges for future high-speed lines. Such types were summarised in Annex E from EN 1991-2. This dataset comprehensively covers the trains loads that can be defined from such regulations.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV