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Resonance and cancellation phenomena in two-span continuous beams and its application to railway bridges
- Source :
- Repositori Universitat Jaume I, Universitat Jaume I
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- The objective of this study is to evaluate the vibratory response of two-span continuous beams subjected to moving loads and, in particular, to investigate the maximum resonance and cancellation of resonance phenomena. The main practical interest is the evaluation of the maximum acceleration response in railway bridges, which is one of the most demanding Serviceability Limit States for traffic safety according to current regulations. Two-span continuous bridges, in their simplest version (i.e. uniform identical spans), present antisymmetric and symmetric modes with closely spaced natural frequencies, leading to a more involved dynamic behaviour than that of simply-supported bridges. First, the free vibration response of a Bernoulli-Euler two-span beam after the passage of a single load at constant speed is formulated analytically, and non-dimensional speeds leading to cancellation or maximum response in free vibration are obtained for each mode. Then, these conditions are equated to resonant speeds induced by equidistant load series, and span length-to-characteristic distance ratios causing cancelled out resonances, or remarkably prominent ones, are obtained. Based on the previous derivations, a methodology for detecting which could be the most aggressive trains for a particular structure based on pure geometrical considerations is discussed. Finally, the applicability of the theoretical derivations is shown through the numerical analysis of two real bridges belonging to the Swedish railway network.
- Subjects :
- Physics
Cancellation
Serviceability (structure)
Antisymmetric relation
business.industry
Numerical analysis
0211 other engineering and technologies
Resonance
020101 civil engineering
02 engineering and technology
Structural engineering
Railway bridges
Two-span continuous beams
0201 civil engineering
Vibration
021105 building & construction
Equidistant
Train
business
Moving loads
Beam (structure)
Civil and Structural Engineering
Subjects
Details
- ISSN :
- 01410296
- Volume :
- 222
- Database :
- OpenAIRE
- Journal :
- Engineering Structures
- Accession number :
- edsair.doi.dedup.....48a19dcc7aff7264744a62f67bf28c24