bluuebunny/crossref_metadata_2025_split huggingface dataset:
A framework for fatigue damage estimate in single-axis solar trackers
Authors: Frontini Giorgio , Argentini Tommaso , Muggiasca Sara , Belloli Marco 
Published: June 2024

Abstract
Solar trackers are constructions consisting of a series of photovoltaic modules mounted on a motorized supporting structure; such systems are usually characterized by limited torsional stiffness and low number of torsional constraints, factors that lead to lower structural frequencies. At these frequencies, trackers are typically susceptible to turbulent wind, and when excited by it, the expected responses can lead to significant deformations and, with its cyclical load variation, also to fatigue damage. On this premise, the presented article proposes a methodology for estimating fatigue damage caused by dynamic wind effects in single-axis solar trackers. As observed in full-scale scenarios, it is assumed that the fatigue damage accumulates in correspondence of the elements connecting the photovoltaic modules to the underlying structure. To this end, a transfer function that relates the pressure acting on the panel to the stress state in a specific point is evaluated with a finite element (FE) model and then experimentally validated with a cyclical load test. Acting forces time histories, derived by wind tunnel measurements, are used with the transfer function to infer the evolution of the stresses acting in the regions of interest. Finally, the rainflow cycle count method is used in conjunction with the Wöhler curve of the investigated structural detail to analyze the stress history and derive a fatigue damage estimate. It is expected that the proposed approach can aid designers in the damage estimation and verification procedures.
BCM-LES for moving cIBM on aeroelastic stability of a tall building with various modes
Authors: Tamura T , Kawaguchi M , Nishiguchi K , Shimada T , Bale R 
Published: June 2024

Abstract
This study analysed the mechanism of unsteady negative pressure around a square cylinder during forced oscillation in the rocking or the first order beam-bending mode, using an advanced large eddy simulation solver on the hierarchical Cartesian grid system using the constraint immersed boundary method for arbitrary moving boundary shape. The study also investigated an onset of negative damping force in relation to the reduced velocity and the oscillation amplitude. The results showed that in the beam-bending mode, the phase of pressure generally advanced more for the reduced velocity defined by the cylinder width, wind velocity and oscillation frequency compared to that of the rocking mode, and the transition to negative damping force occurring at a lower reduced velocity. The findings also indicate that the generation of negative pressure was influenced by timing and location of the vortex formation in the wake of 3D square cylinder.
Bivariate Processes Evolutionary Power Spectral Density Estimation Using Energy Spectrum Equations
Authors: Spanos Pol D. , Matteo Alberto Di , Zhang Hanshu , Yue Qingxia 
Published: June 2024

Abstract
In this paper a novel procedure is developed for evolutionary cross power spectra (ECPS) estimation of bivariate nonstationary stochastic processes. Specifically, the ECPS is determined by estimating the statistical moments of energy-like response quantities of lightly damped linear filters excited by nonstationary stochastic processes. In this context, a smoothing procedure is incorporated by using the Savitzky-Golay (S-G) moving average filter to obtain reliable ECPS based even from a limited number of available records. Further, a refinement of the approach is proposed relying on polynomial based functions of the system output. Several numerical examples, including nonstationary processes with known spectra, and historic accelerograms are used to assess the reliability and accuracy of the proposed procedure.
Noise radiated by ground surface vibrations due to passing trains.
Authors: Jean P , Villot M , Guigou-Carter C 
Published: June 2024

Abstract
Noise radiated by passing trains is usually modelled without considering the radiation of the soil free surface. Models such as TWINS will only consider the acoustic radiation of the different trains and tracks components as a sum of individual acoustic sources defined by their power and directivity expressed in the frequency domain and used as elementary sources in acoustic propagation models. The vibroacoustic model Mefissto, developed at CSTB, can be used to compute the propagation of vibrations from a train to a building as well as the ground borne noise inside lodgings. To compute the noise radiated by the ground free surface one will use the vibration field of a rectangular portion of the surface computed in 3D and evaluate its radiation in the air by means of the Rayleigh integral representation. The Rayleigh integral can be extended by using more complex Green functions, computed by the source image method allowing to consider the presence of one or two buildings. On site acoustic and vibration measurements have been made near a railway line. The calibrated soil model has been used to estimate the noise radiated by the ground which compared to the measured sound pressure levels has showed that the soil radiation is important below 160 Hz.
Some resonance effects of non-typical trains and railway bridges investigated by a frequency-domain method
Authors: Auersch Lutz 
Published: June 2024

Abstract
The resonances of railway bridges have often been analysed for short bridges under periodical high-speed trains, for simply supported one-span bridges, for the fundamental bridge mode, and by time-domain analyses. Many time-consuming calculations have been performed to establish simplified rules for standards. In this contribution, the passage of different (existing, new and hypothetic) trains over different (simply supported, integral, multi-span, continuous) bridges will be analysed in frequency domain by using three separated spectra with the purpose to get a better physical insight in the phenomena. At first, the excitation spectrum of the modal forces is built by the mode shape and the passage time of the train over the bridge. The second spectrum is the frequency response function of the bridge which include the modal frequency, damping and mass. The third part is the spectrum of the axle sequence of an arbitrary train which is not limited to periodical or specific (conventional, articulated, regular or standard) trains and which does not include any bridge parameters. The final solution in frequency domain is obtained as the product of these three complex, strongly varying spectra for the dominating bridge mode or in general as the sum of these products over all relevant bridge modes. The time domain solution is obtained via the inverse Fourier transform, and the resulting time histories have been successfully compared with some measurement results. The method is applied to the vertical and torsional modes of a mid-long single-span bridge on elastomeric bearings under standard train speeds, to a short two-span bridge under high-speed traffic, and to a long three-span integral bridge under long periodical freight trains. Different resonance and cancellation effects have been found for systematically varied train speeds according to the axle sequence of the whole train which is dominated by the two locomotives in that case. To be more specific, the first torsional mode of the mid-span bridge is excited for a train speed of 100 km/h whereas the second bending mode is excited for a train speed of 160 km/h. In both cases, the other mode is suppressed by the minima of the axle-distance spectra. In addition, the case of the German high-speed train ICE4, a Maglev train on a viaduct, and the very high-speed hyperloop case will be discussed briefly. In general, it is shown that resonance effects are also worth to be studied for freight and passenger trains with lower speeds.
Dynamic response of structures with a friction-yield damper
Authors: Titirla M D 
Published: June 2024

Abstract
In this study, the effects of an energy dissipation device in a reinforced concrete building are presented. The damper that is used in this study is part of the passive energy dissipation systems and absorbs the seismic energy through yielding in bending and frictional forces that occur in the metallic elements of the damper. The existence of this friction-yield damper: (i) increases the stiffness of the structure, (ii) absorbs seismic energy, (iii) and controls the axial forces occurring at the diagonal steel braces. The first step of this study is to present the dynamic response of this damper, testing it experimentally under cyclic loading. These experimental results have been compared to the finite element model of the damper results. In addition, a three-story reinforced concrete building is studied in this paper. It is being analysed using push-over and time history analysis, as regards three different cases, (i) the benchmark r/c building (BM3), (ii) the strengthening building with steel diagonal braces (DS3), and (iii) the strengthening building with the investigated damper (DS3-Damper). A comparison of the strengthening solution is presented and further useful results are observed.
On the critical velocity of a mass moving along an infinite beam supported by three viscoelastic layers
Authors: Dimitrovová Z , Mazilu T 
Published: June 2024

Abstract
Numerical assessment of the dynamic behaviour of structures subject to moving loads are under huge development, as are other approaches, to mention e.g. (semi)analytical methods and methods based on frequency-domain moving Green’s function. This contribution is focused on an infinite beam supported by three viscoelastic layers, which, due to its computational efficiency and relatively good approximation of reality, is a quite common model of a railway line. New developments that are presented concern the instability of a moving mass. The critical velocity in this context will be used for the lowest velocity that separates stable and unstable behaviour. The two above-mentioned methods are compared in terms of computational efficiency and accuracy of the obtained results. All results are presented in dimensionless form to cover a wide range of possible scenarios. When the frequency-domain moving Green’s function is used to calculate the critical velocity via D-decomposition method, then a little damping should be considered for numerical stability. The semianalytical approach, on the other hand, can deal with both undamped and damped structures without any problems. Nevertheless, the final results obtained by the two methods (in the Green’s function approach under the assumption of very low damping) are identical.
Studying the effect of delamination on Ostrovsky wave packet propagation in waveguides
Authors: Tranter Matthew R , Tamber Jagdeep S 
Published: June 2024

Abstract
This paper considers the scattering of Ostrovsky wave packets in a delaminated two-layer waveguide with a soft bonding between the layers. The lower layer is significantly denser than the upper layer, so the displacements are described by Boussinesq-Klein-Gordon (BKG) equations in bonded regions or Boussinesq equations in the delaminated regions. A semi-analytical approach is developed using asymptotic multiple-scales expansions, which is less expensive than direct numerical modeling, and good agreement is shown between the two methods. In delaminated regions, the Ostrovsky wave packet evolves into a series of rank ordered solitons with dispersive radiation, and when these solitons re-enter a bonded region, they each evolve into Ostrovsky wave packets, with the lead Ostrovsky wave packet being most distinct. The numerical results are then linked to material parameters, which can motivate physical experiments with a wide range of materials to determine if this measure can be used to control delamination.
Where is the end of a Bridge (model)?
Authors: Bunce Andrew , Hester David , Brennan Daniel S. 
Published: June 2024

Abstract
Bridge SHM solutions have been developed to assist with the assessment and monitoring of bridges. State of the art bridge SHM solutions tend to be data based, where machine learning algorithms are trained using large, historical bridge datasets, and outlier analysis is subsequently used for anomaly detection. However, most bridges lack the required healthy state data for machine learning approaches to be considered, and many bridges are not in a healthy condition to collect the required data from. A population based structural health monitoring (PBSHM) approach has recently been proposed that seeks to facilitate knowledge transfer between similar structures. The approach proposes that if two structures are similar enough, there could be scope to make SHM inferences between the structures. The ability to make inferences between bridges, which are currently monitored in isolation, would be highly valuable as a bridge management tool, particularly if datasets could be leveraged between bridges through transfer learning. However, before knowledge can be shared between bridges, there is first a need to identify bridges that are similar enough for inferences to be made. The PBSHM approach proposes the use of Irreducible Element (IE) models to describe structures, which allows Attributed Graphs (AG) to generated and compared for similarity using graph theory techniques. The general method for comparing structures was trialled on bridges previously, however the resulting similarity metrics were for the whole bridge as opposed to particular common zones of interest e.g. the deck. This paper instead proposes that bridges be modelled as subsections of structures that interact via shared boundaries (i.e., points of articulation such as bearings), as opposed to whole structures. Bridge datasets are often limited to the part of the bridge that was investigated, i.e., datasets particular to bridge decks, abutments etc. Therefore, the extents of the IE models proposed in this paper are set to only include elements that would pertain to a particular dataset. In particular, two beam and slab bridges are each described with bridge deck, abutment and pier IE models to trial the concept. The revised extents of the bridge IE models reduced the number of elements being compared, resulting in increased resolution graph comparisons being carried out and more meaningful similarity metrics between the bridge parts being achieved.
Numerical assessment of the dynamic load allowance on long-span modular steel bridges considering vehicle-bridge interaction
Authors: Chordà-Monsonís J , Moliner E , Martínez-Rodrigo MD , Zacchei E , Tadeu A , Romero A 
Published: June 2024

Abstract
Dynamic effects caused by vehicles on bridges is a key aspect to consider on the designing, monitoring and maintenance of the roadway infrastructure. This is particularly important in the case of modular truss bridges as they face operational restrictions when spans lengths are larger than 60 m. In the recent years, new efforts are being directed to develop fully-functional modular steel bridges of substantially larger spans. For this purpose, it is essential to fully understand the dynamic effect of vehicles on such structures. This paper provides a detailed study on two modular steel bridges considering span lengths from 120 to 140 m. A 3D coupled vehicle-bridge model is used to simulate the vehicle-bridge interaction and evaluate the dynamic load allowance of the structures. Different profiles of road irregularities are generated and their influence is investigated. The results reveal the importance of defects that excite vertical bouncing modes of the vehicle. The effects of considering different span lengths and vehicle speeds are also discussed. Finally, the dynamic load allowance obtained for the bridges under study is compared to that calculated with the expressions given in several design codes.
Residual Life Assessment of Steel Truss Bridge due to Coupled Action of Corrosion and Fatigue
Authors: Ghosh Diptarka , Ashwin Kumar P. C. 
Published: June 2024

Abstract
Steel trusses have often been used as medium to long-span railway-over-bridge structures due to their rapid installation and reliable performance. However, fatigue reduces the service life of these steel bridges. Rapid stress reversals are generated in steel bridges due to the high-speed movement of trains. The damage is further intensified with aging of the structure, due to corrosion. This coupled action of corrosion and rapid stress reversals increase the stress concentration in steel bridges, especially in the vicinity of existing initial defects. Thus, the focus of the current study is to develop a relationship between the residual fatigue life and the coupled deterioration due to corrosion and rail loads, provided in standard railway design guidelines. For the present study, a 63m railway-over-bridge structure modeled in professional design and analysis software is subjected to eleven 25t rail loads taken from Research Designs and Standards Organisation (RDSO) guidelines. The rainflow-counting algorithm has been used to convert critical member’s stress histories into an equivalent set of constant amplitude stress reversals. The obtained equivalent stress histories are applied to the critical member of the steel bridges exclusively modeled using ANSYS. From the numerical results obtained, the residual fatigue life is calculated in terms of number of equivalent sets of varying stress reversal that the simulated member can withstand before failure.
An Efficient Non-intrusive Strategy For Weakly Coupled Fluid-structure Interaction
Authors: Alhayki Eman , Dettmer Wulf G. , Perić Djordje 
Published: June 2024

Abstract
Computational efficiency has remained one of the major barriers constraining the development of computational approaches for simulating many industrial problems involving fluid-structure interaction. The most efficient algorithms are the partitioned staggered solution approaches. These methods require one execution of the solid and fluid sub-solvers per time step. However, such strategies usually lack robustness and efficiency. This work proposes robust second-order accurate staggered solution schemes for fluid-structure interaction. These approaches are based on linear combinations of higher-order predictors and are based on Dirichlet-Neumann coupling. The schemes are unconditionally stable to a high amount of added mass and are suitable for code coupling. The schemes are developed and tested in the setting of one-dimensional model problems, including two dimensional flow around a flexibly supported cylinder.
CFD-Corrected Aerodynamic Influence Matrices and Aplications on Aeroelastic Phenomena
Authors: Utku Gungor O , Burak Nuzumlalı A , Ozkesiciler Müslüm , Kocan Cagrı , Sakarya Evren 
Published: June 2024

Abstract
The main aim of this study is solution of aeroelastic problems such as flutter, gust and control reversal analysis with Computational Fluid Dynamic (CFD) corrected unsteady aerodynamic instead of inviscid linear results calculated by Doublet Lattice Method (DLM). The DLM is the essential tool for calculating unsteady aerodynamic loads in aeroelasticity. Besides the essential advantages of the DLM, it is based on linear potential flow approach and is only valid for subsonic flow with the assumption of thin airfoil geometry. On the other hand, wing tunnel experiments and high fidelity methods such as Reynolds Avaraged Navier Stoke equations (RANS) are traditional ways to improve aerodynamic behavior fidelity. While the experiments and the CFD based solutions give valid results even for transonic region, the cost of them are higher than the conventional DLM method. Hence, the CFD correction methods have been implemented to increase fidelity of the DLM calculations without computational burdens. The challenge here lies in, the mapping/interpolation of external CFD results to DLM boxes and the generation of correction matrices. The authors presents the CFD interpolation and its commercial application on common sense aeroelastic phenomena; flutter, gust and control reversal analysis which are mentioned in aircraft certification documents with CFD corrected aerodynamic. Once the the methods are applied to models in the frame of industrial mandatories. The comparison is made between with and without the CFD correction.
Numerical evaluation of empirical equations for the prediction of building vibrations due to vibratory rollers
Authors: Cao S , Achmus M 
Published: June 2024

Abstract
Vibrations due to construction activities and the resultant oscillation and potential damage of adjacent structures is an important issue in soil dynamics. To prevent damage, the intensity of building vibration on the subsoil and also on the building must be predicted. In most application cases, empirical equations are used to estimate the intensity of vibration (in terms of peak vibration velocity). However, these equations normally do not take site-specific soil conditions into account, but consider an energy term dependent on the construction machine and the distance of the operating machine to the considered building. In the paper, building vibrations due to vibratory rollers are considered. First, empirical approaches from literature are described and compared. Then, a numerical simulation model is presented, which allows the determination of peak vibration velocities due to vibratory roller operation of the soil in the free field as well as of a footing. A parametric study is conducted which shows the effects of subsoil conditions (i.e. soil layering and soil stiffnesses) and footing dimensions on the vibration intensities at varying distances to the vibratory roller. From a comparison of free field and foundation peak velocities, also transmission coefficients from soil to footing are determined.