Publications

Aprendizaje experiencial de Teoría de Estructuras con K’NEX y SAP2000

Este trabajo describe una innovación llevada a cabo durante el curso 2021/22 en las sesiones informáticas de la asignatura “Teoría de Estructuras”, impartida en los grados de Ingeniería Mecánica (asignatura de tercer curso) e Ingeniería en Tecnologías Industriales (asignatura de cuarto curso). Los autores proponen un enfoque práctico con el propósito de diseñar un puente de celosía, combinando una parte experimental de construcción de la estructura con juguetes K’NEX y una sesión de ordenador con el software para análisis estructural SAP2000. La actividad se planificó como una actividad grupal y se programó en tres sesiones: 1) una sesión experimental creativa con K'NEX para proponer un primer diseño, 2) una sesión de modelado con SAP2000 para detectar elementos no eficientes, y 3) una sesión experimental final con K'NEX para proponer un diseño final. La eficiencia de los puentes de celosía propuestos se evaluó mediante la relación entre el peso soportado y el peso de la estructura. Los resultados de esta experiencia son: una mayor motivación y participación de los estudiantes, soluciones muy creativas que superaron las expectativas iniciales y una mejor comprensión del comportamiento de los modelos, especialmente las articulaciones, fuerzas y restricciones de movimiento.

Assessment of Long-Term Structural Health at Villanueva del Jalón Viaduct

On the vertical coupling effect of ballasted tracks in multi–span simply–supported railway bridges under operating conditions

This contribution investigates the vertical coupling exerted by ballasted tracks on the vertical response of bridges composed either of (i) several successive simply-supported spans with weak coupling between them due to the continuous track; or (ii) adjacent single-track decks conforming a double-track bridge, in which interaction effects are induced due to the transverse continuity of the ballast layer. To this end, 2 D and 3 D track-bridge interaction Finite Element models are implemented, which consider a three-layer discrete and explicit idealization of the track. The 2 D track-bridge interaction model is used to perform sensitivity analyses on the track parameters, which have revealed that the ballast shear mechanisms along the track may significantly affect the train-induced vibrations under resonant conditions. Then, the influence of the ballast coupling on the response of twin adjacent decks is investigated with a 3 D track-bridge interaction model. To this end, this model is updated based on the results of an experimental campaign performed on a real bridge composed of two SS spans and two single track twin adjacent decks. The numerical-experimental comparison shows an evident dynamic vertical coupling between the bridge decks and reveals the importance of including the ballasted track in the modelling process of these structures.

Free vibrations of simply-supported beam bridges under moving loads: Maximum resonance, cancellation and resonant vertical acceleration

Two FE models to analyse the dynamic response of short span simply-supported oblique high-speed railway bridges: Comparison and experimental validation

Energy harvesting analysis in railway bridges: An approach based on modal decomposition

Ballast shear effects on the dynamic response of railway bridges

Influence of Ballast Track on Vertical Response of Multi-span Simply-Supported Bridges Under Railway Traffic

Numerical-Experimental Assessment of the SLS for Traffic Safety in Skewed High-Speed Railway Bridges

3D analysis of railway induced vibrations on skew girder bridges including ballast track–bridge interaction effects

ANALYSIS OF THE RESULTS OBTAINED IN A TEST OF BASIC KNOWLEDGE OF MECHANICS AND ELASTICITY IN THE SECOND YEAR OF THE DEGREES IN THE FIELD OF INDUSTRIAL ENGINEERING

ANALYSIS OF THE RESULTS OBTAINED IN A TEST OF BASIC KNOWLEDGE OF MECHANICS AND ELASTICITY IN THE SECOND YEAR OF THE DEGREES IN THE FIELD OF INDUSTRIAL ENGINEERING

PEER-REVIEW OF WRITTEN EXPRESSION IN ENGINEERING REPORTS

Appears in: EDULEARN21 Proceedings Publication year: 2021Pages: 1000-1006ISBN: 978-84-09-31267-2ISSN: 2340-1117doi: 10.21125/edulearn.2021.0259Conference name: 13th International Conference on Education and New Learning TechnologiesDates: 5-6 July, 2021Location: Online Conference

The Free Vibration Response of Elastically Supported Beams traversed by Moving Loads and its Application to Railway Bridges

Effect of the end cross beams on the railway induced vibrations of short girder bridges

Dynamic load allowance of long-span modular steel bridges

Modular steel bridges are structures whose construction is based on regular prefabricated truss units. This presents several advantages, such as rapid and easy deployment, high adaptability to the terrain and reduced construction costs. However, they generally face operational restrictions for span lengths greater than 60m. Recent technological innovations search to overcome these limitations and develop modular structures with larger spans. Hence, the main objective of this work is to evaluate the dynamic effects on long-span modular steel bridges. The present contribution provides a study on two modular bridge typologies, considering different span lengths from 120 to 140m. A 3D coupled vehicle–bridge model is used to analyse the vehicle–bridge interaction and the dynamic load allowance of the structures. The vehicle is represented as a multibody truck system and the bridges are modelled with the finite element method. Several types of randomly-generated road irregularities are considered on the bridge deck. The effect of each type of irregularity is evaluated on the dynamic load allowance of the bridges. The results obtained reveal the notable influence of road irregularities that involve abrupt vertical displacements that excite the vehicle mode shapes. In addition, it is observed that dynamic load allowance indices tend to decrease with longer spans and higher speeds, except when a resonance is produced.

Efficient simulation of the soil–structure interaction on the dynamic response of a portal frame railway bridge

The dynamic response of railway bridges can be highly influenced by the effect of soil–structure interaction. This occurs as the soil dissipates energy and modifies the flexibility of the bridge supports, which impacts the modal parameters of the structure and its response to passing trains. In the case of partially-buried structures such as portal frames, this interaction mechanism is of particular relevance. However, simulating the soil effect is complex, and may require an elevated computational effort. Under these conditions, obtaining accurate predictions of the bridge dynamic behaviour becomes challenging. For this reason, the interplay between the bridge and the soil is usually disregarded. To address this limitation, a numerical approach devoted to implement soil–structure interaction with reduced computational cost is presented in this contribution. The method is based on a substructuring scheme, and considers two numerical models: (i) a full three-dimensional finite-element interaction model, including the track, the bridge, and the surrounding soil, and (ii) a simplified version of it, in which the soil is substituted by a series of linear spring-dampers. The first model is used to derive frequency-dependent dynamic stiffness functions that describe the mechanical coupling between the bridge and the ground. Then, these functions are used to calibrate the spring-damper elements representing the soil in the subsequent simplified model, and the dynamic problem is solved by complex modal superposition. The suitability of the proposed methodology is evaluated through its application to an existing portal frame railway bridge. The effect of other relevant aspects on the bridge response such as the track irregularities and the contribution of the vehicle–bridge interaction is also taken into account. The results highlight the potential of this approach to obtain satisfactory predictions of the bridge performance in an efficient manner.

ANALYSIS OF THE INFLUENCE OF THE BALLAST TRACK IN THE DYNAMIC BEHAVIOUR OF SINGLE-TRACK RAILWAY BRIDGES OF DIFFERENT TYPOLOGIES

Abstract. In the present contribution the coupling effect of the railway track on the dynamic response of single-track bridges with several simply-supported spans is investigated. The response of such structures is of interest due to the possible appearance of high vertical accelerations at the platform, with adverse consequences such as ballast deconsolidation, loss of track stability etc., especially at resonance. Single track railway bridges due to their inherent low mass and damping, are especially critical in this regard.This paper provides a detailed sensitivity analysis over a single track railway bridge catalogue considering lengths of interest from 10 to 25 meters with different typologies: concrete filler beam and concrete slab decks, taking into account and neglecting the vertical flexibility of elastic bearings. To this end, a 2D Finite Element numerical model is implemented admitting a three-layer discrete representation of the track components mass, stiffness and damping, based on [1].The effect of the track on the bridge acceleration response is evaluated. A parametric analysis is presented with the aims of (i) detecting the track parameters that affect the most the bridge vertical acceleration response under railway traffic and (ii) determining what bridges are the most affected by the rigidity and the damping induced by the track components. Additionally, the effect of including several isostatic spans in the model is also evaluated with the goal of concluding where the maximum response occurs and what models are on the safe side.In addition, the experimental response of a real two-span railway bridge belonging to the Spanish railway conventional network is presented under operating conditions. The bridge modal properties identified in a previous work by the authors [2] are employed and the previously described numerical model is calibrated and used to simulate the structural response under railway traffic.Finally, preliminary conclusions are extracted regarding the coupling effect of the track components both at resonant and not resonant conditions.

Experimental Analysis of Arroyo Bracea II Bridge in Madrid – Sevilla High-Speed Railway Line: Dynamic Response of the Structure and Effect of Soil Properties