Pedro Galvín

• Ph.D.
• Professor at University of Seville

This paper investigates energy harvesting on railway bridges. The type of harvester studied is a cantilever bimorph beam with a mass at the tip and a load resistance. These parameters are adjusted to find the optimal design that tunes the harvester to the fundamental frequency of the bridge. An analytical model based on a variational formulation to...

A primary function of railway ballast is to maintain vertical track geometry, however over time it becomes contaminated with fines which reduce its ability to free-drain. Then, in the presence of moisture, the individual particles have greater scope for rearrangement thus leading to increased track settlement. This behaviour has received limited st...

In this paper, the authors investigate energy harvesting on railway bridges. A tuning process based on a statistical analysis of the mechanical energy generated by a lumped‐mass model is presented and validated. A cantilever‐based energy harvester configuration is applied, and the optimal design of 3D printed energy harvesters is studied. The elect...

This work is devoted to the analysis of the dynamic response of High-Speed (HS) multi-track railway bridges composed by girder decks and short-to-medium simply-supported (SS) spans. The vibrational response of such structures may be influenced by three-dimensional (3D) modes (torsion, transverse bending) and, therefore, the use of the typical linea...

Concrete slab railway tracks typically have higher initial capital costs yet lower operational costs in comparison to ballasted tracks. One reason for the elevated operational costs on ballasted lines is the need for more frequent maintenance (e.g. tamping to maintain track geometry). Therefore on higher linespeed routes where maintenance windows a...

This work is devoted to the analysis of the vibratory response of High-Speed (HS) multi-track railway bridges composed by simply-supported spans. In particular, it aims to investigate the influence of three geometrical aspects usually disregarded in numerical models used to evaluate the Serviceability Limit State of traffic safety in such structure...

In this paper, the authors investigate the energy harvesting in railway bridges. An analytical model is proposed for the estimation of the energy harvested from train-induced bridge vibration. The typology of the energy harvester studied in this work is a bimorph beam consisting of two piezoelectric patches on a substructure with a seismic mass. Th...

Single-track railway bridges are susceptible of experiencing high levels of vertical acceleration on the deck that may be dangerously accentuated at resonance. This is especially critical for short-to-medium span simply supported bridges. This problem can compromise the safety of the trains and increase the maintenance costs of the track. The main...

This paper presents a damage identification method for beam-type structures based on the wavelet analysis. The damage location is predicted by a Damage Locating Index (DLI) based on a combined identification of local maxima from the scalograms of mode shapes. A new Damage Severity Index (DSI) based on the Lipschitz exponent is formulated such that...

Railway track geometry deteriorates under repeated train loading. When linespeed is increased or new rolling-stock is introduced this can alter the future rate of change of differential settlement and track geometry. Therefore this paper presents a novel combined engineering-economic approach to investigate the effect of increasing train speeds, ad...

This paper investigates the vibrations induced by humans through in situ behaviour tests of the 516 Arouca footbridge (Portugal), the world’s longest span in 2020 (516 m). The study consists of in situ experimental tests in which the structure was subjected to wind and pedestrian loads. The bridge is first described, to provide design and construct...

Under repeated traffic loading, railway tracks experience settlement which occurs in a non-uniform manner along the track. These differential changes in track profile effect the train-track dynamic interaction forces, which can alter track degradation rates and track geometry quality. Ultimately this results in greater ground-borne vibration. There...

This paper describes a general approach to compute the boundary integral equations that appear when the boundary element method is applied for solving common engineering problems. The proposed procedure consists of a new quadrature rule to accurately evaluate singular and weakly singular integrals in the sense of the Cauchy Principal Value by an ex...

Railway tracks experience different settlement over time due to repeated train passages. Typically, when the standard deviation of this vertical profile exceeds a threshold limit, maintenance (often tamping) is required to correct the profile. Therefore, when planning future maintenance and attempting to optimise track life-cycle cost, it is import...

A novel numerical methodology is presented to solve the dynamic response of railway bridges under the passage of running trains, considering soil–structure interaction. It is advantageous compared to alternative approaches because it permits, (i) consideration of complex geometries for the bridge and foundations, (ii) simulation of stratified soils...

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 indu...

Railway tracks undergo plastic settlement when subject to repeated train loading. This occurs differentially along the track rather than in a uniform manner, and the profile is a key parameter when scheduling track maintenance operations. Therefore this paper presents a novel numerical approach to predict track irregularity evolution. The model com...

This work validates the simplified theoretical, analytical and numerical models used in the preliminary design stage of the 516 Arouca footbridge over the River Paiva (Portugal), the world's longest suspension footbridge. The models were used to define the configuration of the bridge under static loading and the eigenfrequencies excited under dynam...

In this paper the authors investigate the energy harvesting in railway bridges and analyse the performance under different operational conditions. An approximation based on modal superposition is proposed for the computation of the energy harvested from train-induced bridge vibration. This approach is consistent with the analytical modal solutions...

This paper is devoted to track-bridge interaction phenomena in railway bridges of short simply-supported (SS) spans composed by ballasted tracks. These structures may experience high vertical acceleration levels under operating conditions. In particular, the coupling effect exerted by the ballast track shared by structural parts that are theoretica...

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 deconsolidat...

A significant number of railway bridges composed by simply-supported (SS) spans are present in existing railway lines. Special attention must be paid to short to medium span length structures, as they are prone to experience high vertical acceleration levels at the deck, due to their low weight and damping, compromising the travelling comfort and t...

Wavelet analysis can be used in local damage detection due to its ability of revealing discontinuities induced by damage in the displacement field. This paper focuses on the application of wavelet analysis to detect and identify multiple damages using the static deflection of beams. The local damages are located by the wavelet maxima lines and thei...

This work is devoted to the experimental evaluation of the dynamic response of railway bridges with common typologies in short-to-medium span lengths. An extensive experimental campaign is performed in several railway bridges belonging to the High-Speed (HS) and conventional Spanish railway network. The main objectives are to (i) characterise the s...

In this contribution the vertical response of multi-span single-track simply-supported railway bridges is addressed. The main objective is to assess the influence of the track components and its continuity on the bridge acceleration response under the passage of railway convoys. To this end, a preliminary bidimensional numerical model is presented...

Applications are invited from 13/10/2020 to 27/10/2020 for a 4-year #predoc opportunity at Universidad de Sevilla on noise and vibration due to railway traffic within the framework of the research project PID2019-109622RB-C21. ➡️ https://bit.ly/2GH4FpO 🔗 https://bit.ly/30QIcxN

This paper proposes an enhancement of the treatment of non-homogeneous boundary conditions to improve the boundary element method (BEM) formulation. The standard formulation is modified by introducing the boundary conditions in the integral kernels. The boundary conditions are implicitly defined through known parameters depending on the geometry, r...

This work presents a simplified method to evaluate building shaking due to arbitrary base excitations, and an example application to railway problems. The model requires minimal computational effort and can be applied to a wide range of footing shapes, thus making it attractive for scoping-type analysis. It uses the soil excitation spectrum at the...

This work is devoted to the analysis of the railway-induced vertical vibrations of simply-supported double track bridges composed by pre-stressed concrete girder decks. Despite the low torsional stiffness that this particular deck configuration exhibits, several structures of this type do exist in both conventional and high-speed railway lines in S...

The vibrational response of railway bridges is an issue of main concern, especially since the advent of High-Speed traffic. In the case of short-to-medium lengths and simply-supported spans excessive transverse acceleration levels may be induced at the platform, with detrimental consequences for passengers and infrastructures. The orthotropic plate...

This work presents a two-and-a-half dimensional (2.5D) spectral formulation based on the finite element method (FEM) and the boundary element method (BEM) to study wave propagation in acoustic and elastic waveguides. The analysis involved superposing two dimensional (2D) problems with different longitudinal wavenumbers. A spectral finite element (S...

A new hybrid time-frequency modelling methodology is proposed to simulate the generation of railway vibration caused by singular defects (e.g. joints, switches, crossings), and its propagation through the track, soil and into nearby buildings. To create the full source-to-received model, first the force density due to wheel-rail-defect interaction...

This paper proposes a novel boundary element approach formulated on the Bézier-Bernstein basis to yield a geometry-independent field approximation. The proposed method is geometrically based on both computer aid design (CAD) and isogeometric analysis (IGA), but field variables are independently approximated from the geometry. This approach allows t...

Structural health monitoring consists of structural integrity assessment by means of data acquisition and analysis from on-board sensors. Fiber Bragg grating–based monitoring is increasingly attracting the scientific community working on structural health monitoring due to its multiple advantages such as electromagnetic immunity, negligible weight...

The number of railway lines both operational and under construction is growing rapidly, leading to an increase in the number of buildings adversely affected by ground-borne vibration (e.g. shaking and indoor noise). Post-construction mitigation measures are expensive, thus driving the need for early stage prediction, during project planning/develop...

Railway induced vibrations on short-to-medium span simply-supported (SS) bridges is addressed in this contribution. Such structures may experience high levels of vertical acceleration at the platform, leading to adverse consequences such as a premature degradation of the ballast layer and passenger discomfort. In the present study, the evolution of...

In this paper the dynamic response of a particular type of high-speed railway bridge common in the Spanish railway system is analysed with the aim of evaluating the levels of vertical vibrations experienced at the platform. To this end, Bracea I bridge which belongs to the Madrid-Sevilla High Speed railway line is selected. The bridge is composed b...

This work presents a fast computational approach to quantify the ground vibration generated by the passing of urban railway vehicle over localized defects (e.g. rail joint or turnout). The methodology is based on a two-step simulation where the vehicle/track/foundation and track/soil dynamics are calculated separately. The vehicle/track interaction...

This paper presents a novel formulation of two spectral elements to study guided waves in coupled problems involving thin-walled structures and fluid-acoustic enclosures. The aim of the proposed work is the development of a new efficient computational method to study problems where geometry and properties are invariant in one direction, commonly fo...

This paper uses the Continuous Wavelet Transform Analysis on mode shapes for damage identification. The wavelet analysis is applied to the difference in the mode shapes between a healthy and a damaged state. The paper also includes a novel methodology for estimating the level of noise of the experimental mode shapes based on a standard Signal to No...

Traffic induced vibrations in railway bridges has become an issue of main concern among scientists and engineers due to the extensive construction of new High-Speed railway lines and the upgrading of existing lines for higher operating velocities [1, 2]. In this context, short to medium-span bridges (10–25 m) composed by simply-supported elements a...

This work presents a scoping model to predict ground-borne railway vibration levels within buildings considering soil-structure interaction (SSI). It can predict the response of arbitrarily complex buildings in a fraction of the time typically required to analyse a complex SSI problem, and thus provides a practical tool to rapidly analyse the vibra...

In this paper, we propose a spectral element method (SEM) to study guided waves in coupled problems involving thin-walled structures and fluid-acoustic cavities. The numerical method is based on the subdomain decomposition of the fluid-structure system. Two spectral elements are developed to represent the fluid and the structure. A plate element ba...

In this contribution the authors include results and conclusions from an experimental and numerical analysis of a railway bridge belonging to the Madrid-Sevilla High-Speed railway line in Spain. This structure is monitored due to its short length and typology, which make it susceptible to experience high transverse vibration levels. During the in-s...

Structural Health Monitoring is considered the process of damage detection and structural characterization by any type of on-board sensors. Fibre Bragg Gratings (FBG) are increasing their popularity due to their many advantages like easy multiplexing, negligible weight and size, high sensitivity, inert to electromagnetic fields, etc. FBGs allow obt...

This work presents a scoping model to predict ground-borne railway vibration levels within buildings considering soil-structure interaction (SSI). It can predict the response of arbitrarily complex buildings in a fraction of the time typically required to analyse a complex SSI problem, and thus provides a practical tool to rapidly analyse the vibra...

The efficiency of two coupling formulations, the boundary element method (BEM)-meshless local Petrov–Galerkin (MLPG) versus the BEM-finite element method (FEM), used to simulate the elastic wave propagation in fluid-filled boreholes generated by a blast load, is compared. The longitudinal geometry is assumed to be invariant in the axial direction (...

This paper presents a numerical method based on a two-and-a-half dimensional (2.5D) boundary element-finite element (BEM-FEM) coupled formulation to study noise and vibration from underground structures. The proposed model properly represents the soil-structure interaction problem and the radiated noise and vibration. The soil is modelled with the...

This work presents a scoping model to predict ground-borne railway vibration levels within buildings considering soil-structure interaction (SSI). It can predict the response of arbitrarily complex buildings in a fraction of the time typically required to analyse a complex SSI problem, and thus provides a practical tool to rapidly analyse the vibra...

The dynamic transverse response of beam type bridges under railway traffic is addressed in this contribution. In particular, how soil-structure interaction may affect the critical or resonant velocities and the associated vibratory amplitudes is evaluated in detail. Resonance in beams, due to the circulation of equidistant loads, is highly influenc...

The response of wind turbines is induced by dynamic loads such as wind, transient and cyclic loads, and also extreme loads such as earthquakes. Thus, the structural design requires an accurate evaluation of the modal parameters of the system because it is strongly required that no resonances are excited. Moreover, it has been concluded from previou...

In the present contribution, the dynamic behaviour of beams traversed by moving loads including soil–structure interaction (SSI) is investigated. The main application of the study is to analyse the effects of SSI on the resonant response of bridges caused by railway traffic. As this phenomenon is highly influenced by the free vibration response of...

One of the main challenges in damage detection techniques is sensitivity to damage. During the last years, a large number of papers have used wavelet analysis as a sensitive mathematical tool for identifying changes in mode shapes induced by damage. This paper analyzes the effect of adding a mass to the structure at different positions. Depending o...

This paper provides new insights into the characteristics and uncertainties in railway ground-borne vibration prediction. It analyses over 1500 ground-borne vibration records, at 17 high speed rail sites, across 7 European countries. Error quantification tests reveal that existing scoping models, for at-grade tracks, are subject to a mean error of...

We describe a hybrid method to study fluid and solid interaction problems in the frequency domain. The numerical method is based on subdomain decomposition. The BEM is used to model unbounded solid mediums, whereas the confined subdomains, both fluid and solid, are represented by the FEM. The analysis is carried out by superposing two-and-a-half di...

This paper presents a numerical method based on a three dimensional boundary element-finite element coupled formulation in the time domain. The proposed model allows studying soil–structure interaction problems. The soil is modelled with the boundary element method, where the radiation condition is implicitly satisfied in the fundamental solution....

This paper presents the dynamic soil–structure analysis of the main telescope T250 of the Observatorio Astrofísico de Javalambre (OAJ, Javalambre Astrophysical Observatory) on the Pico del Buitre. Vibration control has been of prime concern in the design, since astrophysical observations may be hindered by mechanical vibration of optical equipment...

Environmental vibrations due to railway traffic are predominantly due to dynamic axle loads caused by wheel and track unevenness and impact excitation by rail joints and wheel flats. Because of its irregular character, track unevenness is commonly processed statistically and represented by its power spectral density function or its root mean square...

The wavelet transform has proven to be a useful mathematical tool to detect changes in the mode shapes of a structure and therefore to detect damage. The authors have proposed a damage detection methodology based on the wavelet analysis of the difference of mode shapes corresponding to a reference state and a potentially damaged state. The wavelet...

This paper presents a numerical method based on a three dimensional boundary element–finite element (BEM–FEM) coupled formulation in the time domain. The proposed model allows studying soil–structure interaction problems. The soil is modelled with the BEM, where the radiation condition is implicitly satisfied in the fundamental solution. Half-space...

This paper presents 2 methodologies based on the Boundary Element Method and the Finite Element Method to study soil-structure interaction effect on building behaviour. A 3-story building response induced by an incident wave field is studied using both methods. The results obtained show a good agreement. Then, a simplified model is validated from t...

This paper presents a new damage detection methodology for beams. It applies wavelet analysis to locate the damage from changes in the mode shapes (geometric based analysis). The proposed methodology requires the mode shapes of a reference undamaged state as well as those of the potentially damaged one. Once obtained, a continuous wavelet transform...

This paper applies a methodology for damage detection in beams proposed by the authors. The methodology is based on a continuous wavelet analysis of the difference of mode shapes between a damaged state and a reference state. The wavelet transform is used to detect changes in the mode shapes induced by damage. The wavelet coefficients for each mode...

This paper explores dynamic soil-bridge interaction in high speed railway lines. The analysis was conducted using a general and fully three-dimensional multi-body finite element-boundary element model formulated in the time domain to predict vibrations caused by trains passing over the bridge. The vehicle was modelled as a multi-body system, the tr...

Dynamic soil–structure interaction is concerned with the study of structures supported on flexible soils and subjected to dynamic actions. Methods combining the finite element method (FEM) and the boundary element method (BEM) are well suited to address dynamic soil–structure interaction problems. Hence, FEM–BEM models have been widely used. Howeve...

In this work the numerical model SSIFiBo developed in MATLAB to study dynamic soil-structure interaction problems is presented. The model is based on a three dimensional boundary element-finite element coupled formulation in time domain. This model allows computing structural forced-vibrations, as well as seismic responses. Two numerical examples a...

This paper presents the results of an innovative teaching experience in the area of structural analysis in the mechanical engineering program of the Universidad de Sevilla, Spain. The teaching methodology used is aimed at motivating students to learn by promoting the design, calculation, building, and testing of structures. This method not only tra...