bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intelligent Automatic Operational Modal Analysis: preliminary results
Authors: Rosso Marco Martino , Aloisio Angelo , Marano Giuseppe Carlo , Quaranta Giuseppe 
Published: June 2024

Abstract
Within the structural health monitoring (SHM) field, consistent research efforts have been invested in developing automatic vibration-based indirect methodologies for inspecting existing heritage conditions. Current trends are mainly focused on output-only automatic operational modal analysis (AOMA), specifically throughout the stochastic subspace identification (SSI) technique among others. In the literature, a widespread workflow is implemented in a four-step solution: choice of the SSI control input parameters, computation of stabilization diagrams, stable poles’ alignments detection, and their final clustering. However, the so far proposed solutions have not provided yet complete answers to some challenging and still open questions. For instance, an arbitrarily poor initial choice of the SSI control parameters may jeopardize the entire procedure. Therefore, in the current study, the authors present a novel intelligent-based AOMA framework in a machine learning perspective. Specifically, random-forest-driven Monte Carlo sampling of control parameters represents a promising intelligent way to automatically choose the proper SSI control parameters. Furthermore, the recurrent stable physical poles in the stabilization diagram among the Monte Carlo simulations deliver some special insights about mode shape confidence intervals. A numerical benchmark is herein analyzed illustrating some preliminary results and potentials of the proposed methodology.
Analysis of the dynamic behavior in a masonry dome in the city of Florence: Chiesa di Santa Maria del Fiore’s Dome
Authors: Vitorino S , Corazzi R , Doz G 
Published: June 2024

Abstract
Masonry construction has been practiced for thousands of years, being an important part of the world’s cultural heritage, containing sociological, economic, cultural and political elements of the place where it is inserted, physically offering us the opportunity to research and learn about the past. The analysis and prediction of historical structures behaviour over the years constitute a fundamental field of research to perpetuate the construction methods and the cultural heritage of civilizations. Such analyses involve not only the static aspect of the constructions but must also include the seismic action, not only due to the possible damages generated to the structure, but also, to the uncertainties associated with the occurrence of this phenomenon in the patrimonial and social security. In this context, the urban area of the Italian municipality and capital of Tuscany, Florence, which became a symbol of the Renaissance during the early Medici period and has the greatest concentration of universally renowned works of art associated with events of universal importance, is located in a seismic zone, with episodes of earthquakes in May 2022, with a magnitude of up to 3.7Mw. Thus, the present work aims to numerically analyse the dynamic behaviour and safety of the main masonry dome in the historic center of Florence: Dome of Santa Maria del Fiore’s Cathedral. For this, it was used the structural analysis software by the finite element method ABAQUS, and the numerical models were validated using the results of experimental analyses, present in the literature. The final model, which adequately reproduces the experimental results, can be used as part of a permanent monitoring system for the structural health of the dome and the prevention of possible damage.
An application of different surrogate models to model updating of a heritage structure
Authors: Rosati I , Fabbrocino G , Rainieri C 
Published: June 2024

Abstract
The preservation of historic structures is of primary importance due to their significant cultural value. However, destructive tests as well as invasive interventions should be as much limited as possible. In this contest, Finite Element model updating can be applied as a non-destructive method to indirectly estimate selected unknown parameters through numerical model calibration. To this aim, an inverse problem has to be solved by minimizing the gap between corresponding experimental and numerical estimates of modal parameters. However, the application of Finite Element model updating is usually associated with large computational efforts. These can be reduced through the choice of a suitable surrogate model. Douglas-Reid method and Response Surface method are frequently applied to this aim due to their relatively simple quadratic formulations. In spite of the similarity of the mathematical formulation of the surrogate models in the two cases, the methods show some peculiarities affecting their application and, in some cases, their performance. The present paper illustrates an application of Douglas-Reid method and Response Surface method to a historical building, reporting a comparative assessment of the two approaches in terms of computational time and model updating results.
Dynamic monitoring of the Temple of Neptune in Paestum (Italy) - Preliminary results
Authors: Petti L , Lupo C , D’Angelo T 
Published: June 2024

Abstract
This paper focuses on an experimental monitoring system developed for the Temple of Neptune in Paestum within a joint research project carried out by the Department of Civil Engineering (DICIV) at the University of Salerno and the Archaeological Park of Paestum and Velia (PAEVE).This monitoring system is an innovative seismometric network consisting of mechanical and electronic components of high sensitivity and precision, allowing the assessment of the static and dynamic response of the structure in order to monitor its evolution over time and support proactive maintenance activities. In particular, the paper presents the monitoring network and discusses the preliminary results highlighting the contribution that such an innovative system can provide to a broader maintenance process. The results confirm the high level of accuracy and stability of the overall system, as well as preliminary correlations between the temple’s daily response and weather changes such as temperature.
An Experimental Investigation Into Non-Contact Measurements for Leak Detection Using a Commercial Camera to Measure Vibration
Authors: Campos B C , Brennan M J , Gonçalves P J P , Iwanaga M K , Rustighi E , Matos P H M C , de Almeida F C L 
Published: June 2024

Abstract
Leaks in water distribution systems are a major problem as a large amount of water is wasted between treatment plants and consumers. Water supply companies use different strategies to identify and locate leaks in their pipe networks, among which, vibro-acoustic methods and devices (i.e. listening sticks, geophones, and leak noise correlators) are the most popular. Although single-point listening devices are cheap and simple to use, they rely on the operator’s hearing training. Moreover, this may lead to a search based on trial and error as only vibration intensity is used, so no information regarding the leak direction is available to aid in its location. Leak noise correlators, however, use two sensors and a leak can be pinpointed by estimating the time of flight between the two measured signals together with knowledge of the speed at which the leak noise propagates. These sensors need to be directly placed on the pipe or a pipe fitting. This paper concerns an investigation of a new technique, where leak noise signals measured using cameras (non-contact measurements), are pre-processed using computer vision techniques to extract meaningful information regarding vibration due to a leak. Here, this is conducted in controlled conditions by using a test bench that simulates the vibration response of a buried pipe at two measurement positions. Tests are carried out to evaluate the camera sensitivity regarding the distance from the signal source, lighting, contrast intensity, and the relation between image resolution and detection of a simulated leak are performed. The results are compared to classic contact measurements made using accelerometers, showing that the proposed technique is promising for leak detection. Moreover, this comparison is conducted using classical signal processing tools such as Power Spectral Density (PSD), modulus and phase of the Cross-Power Spectral Density (CPSD), coherence and Cross-Correlation Coefficient (CCC).
On the identification of aerodynamic derivatives using forced vibration in active grid generated turbulent flow
Authors: Kildal Oddbjørn , Petersen Øyvind W , Øiseth Ole 
Published: June 2024

Abstract
Aerodynamic derivatives are widely used to model the self-excited forces on bridges and for estimating the corresponding flutter stability limit. It is currently unclear to which degree the aerodynamic derivatives of a cross-section depend on the presence of turbulence in the incoming flow. However, it is believed to depend on the cross-section. In this study, wind tunnel experiments were conducted with forced vibration testing to investigate whether aerodynamic derivatives for a twin deck cross-section changed with increasing turbulence and whether longer measurement periods would yield less uncertainty in the estimated aerodynamic derivatives. Critically, large scatter in the wind tunnel experimental results was observed. Numerical simulations were run to investigate the uncertainty of aerodynamic derivatives related to turbulence and the length of the measurement period. It was shown that the presence of buffeting forces might disturb the identification of aerodynamic derivatives and that the uncertainty of the aerodynamic derivatives decreases for longer measurement periods. Real changes in aerodynamic damping due to turbulence are shown to be probable despite the shortcomings of the system identification procedure.
Design, Wind Tunnel Tests, Normative and Theoretical Approaches of the ARC MAJEUR Subject to Vortex Shedding
Authors: Palm A , Duchêne Y , de Ville de Goyet V , Denoël V , Andrianne T 
Published: June 2024

Abstract
The monumental work of art by Bernar Venet, called ‘Arc Majeur’ wraps the Belgian motorway E411 at Lavaux-Ste-Anne, offering drivers an unmissable landmark in the landscape. This sculpture is a curved steel structure with a height of 60 meters and a 2.25 meters square section. Due to its slenderness, lightness and low vibration frequencies, the structure is very sensitive to wind excitations and mainly to vortex induced vibrations (VIV). After the presentation of the design and the main properties of the structure, the paper presents two approaches to estimate VIV amplitudes. The first one details the mathematical models of VIV included in the Eurocode and several theoretical approaches. The second approach compares the mathematical models to the results of experiments conducted in the wind tunnel facility of the University of Liège. The influence of several parameters is investigated. The experiments revealed lower VIV amplitudes than the theoretical approaches. As the Arc Majeur cannot withstand the fatigue induced by the VIV, it is mitigated by increasing the damping ratio by adding a tuned mass damper (TMD) at the top. Due to the vital importance of its operation, an online processing is developed to verify that the damper operates as intended.
Alongwind dynamic response of slender vertical structures: thunderstorm outflows vs extra-tropical cyclones
Authors: Roncallo L , Tubino F , Gimondo M 
Published: June 2024

Abstract
This paper studies the maximum dynamic response of a slender vertical structure subjected to thunderstorm outflows and provides a comparison with synoptic events. A reinforced concrete telecommunication tower is considered as case study. The thunderstorm wind speed is modelled as sum of a slowly-varying mean and nonstationary turbulent fluctuations with a vertical nose profile, while for synoptic wind the Italian CNR Guideline is adopted. A reference wind speed with 50 years return period is considered for both the thunderstorm and synoptic events, based statistical analyses carried out on in previous studies. In view of the results outlined for the considered structure, the thunderstorm wind loading, which is currently not accounted by codes and standards, can be more demanding than synoptic events.
Multimodal aeroelastic analysis of suspension bridges with aerostatic nonlinearities
Authors: Russo S , Piana G , Carpinteri A 
Published: June 2024

Abstract
A one-dimensional (1D) continuum model for the multimodal aeroelastic analysis of suspension bridges is presented which refines a previous model by some of the authors. The classical linearized equations governing the (self-excited) bridge vertical and torsional oscillations are enhanced to include geometric stiffness contributions related to the steady lift and drag forces. A multi-degree-of-freedom (MDOF) system is obtained by Galerkin method and, for increasing values of wind speed, the damped linear dynamics, modulated by both the steady and the self-excited aerodynamic forces, is studied in the complex field. Stability thresholds for divergence and flutter are determined by the classical Lyapunov dynamic criterion. Selected engineering case studies are considered to demonstrate the capabilities and the validity of the proposed model and of the relevant numerical code. In a comprehensive dynamic framework, the method allows for: (i) determining the variation of the bridge mode shapes and frequencies for increasing values of wind speed, including an effective description of the coupling between the two displacement components as well as the interaction between different vibration modes; (ii) detecting both single-degree-of-freedom (i.e. damping-driven) and coupled (i.e. stiffness-driven) flutter instability; (iii) detecting static divergence instability; and (iv) investigating geometric nonlinearities associated with the aerostatic load.
Bayesian Statistics to determine Aerodynamic Admittance based on measurements at a high-rise Building
Authors: Kemper F.H. , Geurts C.P.W. 
Published: June 2024

Abstract
For the modeling of stochastic structural responses due to wind gusts, it is reasonable to make elementary assumptions for the aerodynamic admittance. However, there are still a large variety of corresponding models, and there is a lack of validation and reliable model estimation studies based on real data. In this paper, real data from a high-rise tower in Rotterdam are used to identify the aerodynamic admittance (size-effect and joint-acceptance functions, SEF and JAF) using inverse modeling based on Maximum Likelihood Estimates (MLE), Markov-Chain Monte Carlo (MCMC) sampling, and a Bayesian posterior (BP) implementation to find parametric models for both aspects of the aerodynamic admittance.
Quadratic Basis Pursuit in Model Updating of Underconstrained Problems
Authors: Bernal Dionisio , Ulriksen Martin D. 
Published: June 2024

Abstract
This paper considers the extraction of sparse solutions using the L1 minimization surrogate for two approximations of the nonlinear relation between parameters and features; in the first, nonline-arity is discarded altogether and in the second a quadratic relation is assumed. The associated algorithms are the well-known Basis Pursuit (BP) and the more recently introduced Quadratic Basis Pursuit (QBP). It is contended that measuring success by comparing the extracted solutions with the underlying truth is unnecessary, as all that’s needed from the extractor is to identify a sufficiently small parameter set to render the problem determined. Specifically, with p as the number of features, one is interest in the likelihood that the algorithm leads to Ω
p
∩ Θ = Θ, where Θ = true set and Ω
p
= set of the largest p non-zero entries in the solution. When operating in this manner the disruption that nonlinearity brings into the BP solution derives only from the nonlinearity induced rotation of the right-hand side away from the span of the column partition of the Jacobian for the non-zero entries. From this perspective one expects performance to deteriorate only weakly with the extent of damage and this result is numerically con-firmed. It is found that although QBP has the quadratic premise as an advantage over BP, the perfor-mance in simulations, due to the difficulty in obtaining optimal values for the free parameters (and the fact that damage extent prediction was not relevant) proved somewhat poorer than BP.
Cone penetration tests and dynamic soil properties
Authors: Schepers W , Kulke D 
Published: June 2024

Abstract
Current standards like ISO 14837-32:2015 and DIN EN 1998-1/NA:2021 as well as prEN 1997-2:2022 allow for using correlations between the results of in-situ soil penetration tests and shear wave velocity (or shear modulus) to determine soil properties to be used in dynamic analyses. While the ISO and prEN standards even provide some recommendations on specific correlations to be used, the DIN standard does not. Due to the statistical nature of such correlations their general applicability has to be verified. We collected data sets from test sites from Germany as well as New Zealand at which cone penetration tests (CPT) as well as seismic site investigation methods were conducted. These sites comprise sandy soils as well as clayey soils, mixed soils as well as glacial soils. We compare the results of several correlations between CPT results and shear wave velocity. The accuracy of such correlations is assessed with respect to the accuracy of seismic in-situ tests. It turns out that for clean sands such correlations between CPT and V
s have a similar order of variability as seismic in-situ tests conducted at the same site. The higher the fines portion of the soil, the higher the variability of the statistical correlations, and consequently the less the general applicability. For glacial soils and other special soil types usage of statistical correlations to determine dynamic soil properties is not recommended.
Wireless Sensor Network-Based Systems for Monitoring a Lifting Bridge
Authors: Kilic Gokhan 
Published: June 2024

Abstract
Assessing the health and condition of structures like bridges involves frequently using structural health monitoring (SHM). In the past, wire sensors had to be installed on bridge structures as part of the SHM process so that data could be collected and sent to a data gathering unit there. However, this study suggests switching out the conventional wire sensors with wireless ones to create a Bridge Health Monitoring System (BHMS) that is affordable, practical, and simple to install. A software translation program attached to the monitoring server is used by each wireless sensor. In a GSM LAN (Global System for Mobile Communications) environment, this monitoring server system has the ability to link and interact with other similar systems of that type. The evaluation approach provided by the BHMS is thorough, secure, and portable.
Dynamic Responses and Associated Permanent Deformation of Ballasted Trackbed Due to Train Passages at High Speed
Authors: Gao Zelei , Bian Xuecheng 
Published: June 2024

Abstract
The ballasted trackbed plays a crucial role in railway infrastructure. However, as train speeds escalate, it experiences heightened vibrations and substantial permanent deformation, posing a notable threat to normal train operations. This study is dedicated to investigating the dynamic response and associated irreversible deformation of railway ballast under varying train speeds, with a specific focus on particle-scale manifestations. To accomplish this, a comprehensive ballasted trackbed model, encompassing the entire transversal cross-section, was built using the discrete element method (DEM) with realistic polygonal elements. The DEM model underwent preliminary validation against measurements from full-scale model tests and was subsequently employed to simulate the mechanical behavior of the ballasted trackbed under various train speeds. The findings reveal that increased train speeds lead to vigorous shaking of ballast particles, manifesting as intense vibration at the macroscopic level of the track structure. The heightened particle activity indicates instability in the inter-particle contact network and distinctive particle migration. Consequently, a notable accumulation of permanent deformation occurs in the granular trackbed. Notably, once the train speed surpasses a certain threshold, there is observable migration of ballast particles beneath the sleeper towards both ends. This phenomenon results in the absence of a stabilized inter-particle contact network to support the upper train load, leading to rapid and significant irreversible deformation in the ballasted trackbed.
Monitoring of thermal deformations of a highway bridge: Comparison of geodetic measurements, finite element simulations and AI predictions
Authors: Lorenz R , Petryna Y 
Published: June 2024

Abstract
Structural Health Monitoring of civil engineering structures is experiencing an increasing progress in the last decades. The present work focuses mainly on static behaviour of a highway bridge due to environmental temperature effects. The first goal is to compare the results of the finite element simulations to the classical geodesy surveying measurements for deformation monitoring of a large, curved highway bridge. The second goal is to test the applicability of artificial intelligence (AI) methods to predict such deformations online without comprehensive computer simulations. In this context, it is also shown how AI can be used to compensate outage of the measurement system and as an element of a monitoring system for system change detection.
Real-world data-supported and higher-order element theory-enabled progressive damage model assembly
Authors: Pei Jin-Song , Chatzi Eleni 
Published: June 2024

Abstract
Dynamic responses of steel bolts anchored in concrete and subjected to cyclic loads are complex: Qualitative physical attributes include pinching, displacement drift and force-intercept. In fact, these attributes vary with time, involving uncertainties that can lead to different failure patterns. This study explores higher-order elements (HOEs), an emerging theoretical macro-modeling framework originated from electrical engineering and transferred to engineering mechanics by using physical analogies. This study proposes a systematic procedure for a new model formulation – a model assembly that is made up of three distinct modeling elements, a higher-order spring, higher-order damper, and loading-rate independent damper to capture pinching, displacement drift, and force intercepting, respectively. The two higher-order elements play significant roles to model responses of fatigue loading in two opposite directions each involving loading and unloading. To afford more physical insights, the higher-order spring is further formulated into a mem-spring, where new choices of state variables are employed. The proposed model formulation benefits both efficient simulation of time-varying dynamical systems and qualitative failure analysis. In addition, this study offers a case study to reveal a new utility of HOE theory. Two major datasets of anchoring blots are used to develop and validate the proposed modeling approach, while three minor datasets are used for a supplementary investigation. This study shows that, both qualitatively and quantitatively under ordered excitation, HOE can be employed with more modeling power and efficiency compared with existing models for progressive damage, and with the flexibility to interface with some existing models when needed.