Alternative methodologies to the semi-analitic solution to the problem of moving loads on high speed railway bridges based on the sensitivity of the response to train speed and on hilbert transformation
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AuthorGarcía Macías, Enrique
DirectorMartínez Castro, Alejandro E.
DepartamentoUniversidad de Granada. Departamento de Mecánica de Estructuras e Ingeniería Hidráulica
SponsorshipUniversidad de Granada. Departamento de Mecánica de Estructuras e Ingeniería Hidráulica. Máster Universitario en Estructuras, curso 2012-2013
Abstract.- Nowadays, modernity and high speed rail are terms inevitably coupled. The bad experience in the predominance of the transportation by the road over the rest of ways of transportation makes societies ask for new sustainable and efﬁcient way of transportation, role for which high speed rail is positioned to be one of the most important pieces. Because of this, Engin- eering must be prepared to plan these new structures and face the design of them according to the sensitive social conscience about something as important as the transportation. From the point of view of the design, high speed bridges are structures whose dynamic response conditions the while design process. Nevertheless, despite the more than foreseeable increase demand on these structures, the dynamic analysis techniques keep on using approx- imate techniques based on step by step methodologies, methods that discretize as much time as space. Semi-analytic solution supposes a great improvement on dynamic analysis of high speed bridges subjected to moving load because it only discretizes space but it is exact on the time domain. However, despite being a more accurate and fast methodology in the analysis, today it still requires great amount of time of calculus and computational costs in the analysis of great tridimensional structures. This fact is more critical in design process in which the engineer must deliberate between several alternatives for the ﬁnal design, having to employ great amounts of time in each one of them. The present research proposes two new methodologies based on Semi-Analytic solution but optimized in the two main variables of the analysis, time and velocity stepping, thanks to its analytical properties in the time domain what allows a deep mathematical treatment of the formulation. On one hand, the ﬁrst proposed method is called the dq/dv method, and it deﬁnes the response of the structure through the determination of its sensibility to velocity what allows higher velocity sampling. On the other hand, it is deﬁned a new methodology through the application of the Hilbert transformation of the signals what allows a higher time samplig, the other main variable. The relevance of this two new methodologies lays on their applicability in pre-design phases, in which the reduction of computational cost and time of calculus can be very important.