530 research outputs found
Direct simulation of the tensioning process of cable-stayed bridges
No full textThis paper proposes a new and innovative algorithm, the Direct Algorithm (DA), which introduces, for the very first time, the unstressed length of the stays concept into the modeling of the construction process of cable-stayed bridges. This assumption enables a fast and direct simulation of construction stages by analyzing independent Finite Element Models when time-dependent phenomena are neglected. The computational speed and the limited computer storing requirements of the DA make it especially indicated for optimization problems. Furthermore, it can be implemented in any structural analysis software. (C) 2013 Elsevier Ltd. All rights reserved.Part of this work was done through a collaborative agreement between University of Castilla-La Mancha (Spain) and Tongji University (China). This included an exchange of faculty and scholars. The financial support from Kwang-Hua Foundation from College of Civil Engineering of Tongji University and from the International Relation Office of University of Castilla-La Mancha is greatly appreciated.Lozano Galant, JA.; Xu, D.; Paya-Zaforteza, I.; Turmo Coderque, J. (2013). Direct simulation of the tensioning process of cable-stayed bridges. Computers and Structures. 121:64-75. doi:10.1016/j.compstruc.2013.03.010S647512
Comparison of different low-cost sensors for structural health monitoring
No full textRecently, the need for Structural Health Monitoring (SHM) and inspection is growing as a result of the increasing age of the structural stock worldwide. SHM includes bringing into use a sensor or an array of sensors into an engineered structure. This paper evaluates the practical aspects to consider when choosing different low-cost sensors for using in a SHM application. For this reason, a microcontroller (Arduino) with attached sensors (Ultrasonic, Laser, Gyroscope, Accelerometer, Temperature-humidity, SD-module) has been used throughout different controlled ambient situations and experiments. During the sensor installation and data acquisition, some issues related to the Arduino codes and position of the sensors arise. In this article solutions for tackling faced problems have been presented for achieving an efficient way of using these electronic devices. Their data have been collected to assess and compare their tolerances as well as advantages and disadvantages of their use, cost among them. The information from this article could be used either to choose the appropriate sensors either for static or for dynamic Structural System Identification (SSI).The authors are indebted to the Spanish Ministry of Economy and Competitiveness for the funding pro-vided through the research project BIA2017-86811-C2-1-R directed by José Turmo and BIA2017-86811-C2-2-R, directed by Jose Antonio Lozano-Galant. All these projects are funded with FEDER funds. Authors are also indebted to the Secretaria d’ Universitats i Recerca de la Generalitat de Catalunya for the funding provided through Agaur (2017 SGR 1481). It is also to be noted that funding for this re-search has been provided for MR. SEYEDMILAD KOMARIZADEHASL by Agencia Estatal de Inves-tigación del Ministerio de Ciencia Innovación y Universidades grant and the Fondo Social Europeo grant (PRE2018-083238).Postprint (published version
Accelerated viaduct construction
No full textModern geometrical requirements for high capacity ground infrastructure, as highways or high speed train lines, imply increasing number of long tunnels and viaducts in mountainous countries. Moreover, for the sake of the environment, only some selected construction methods are eligible for sensitive areas. Among them, a very popular one for medium span concrete viaducts is the span by span construction with movable scaffolding system. The method can be easily adapted to any geometry and, from an environmental point of view, only the shadow of the deck is spoilt during construction periods. Since its first application in the Kettiger Hangbrücke, (Germany) in 1959, this construction method has been applied extensively all around the world. The paper will describe the pros and cons of the method and will explain in detail the last developments made in order to reduce to a minimum the critical path, increasing its competitiveness. New construction sequences, non-standardized structural details, static and dynamic tests, finite element model analysis and recent already built examples will be described to illustrate the possibilities of the method.The author are indebted to the Spanish Ministry of Economy and Competitiveness for the funding provided through the research project BIA2017-86811-C2, funded with FEDER funds. Authors are also indebted to the Secretaria d’ Universitats i Recerca de la Generalitat de Catalunya, Spain, for the funding provided through Agaur (2017 SGR 1481). The author wants to thank also Mr. Roberto Soto, from Mecanotubo S.A., for all his support.Postprint (published version
Accelerated viaduct construction
No full textModern geometrical requirements for high capacity ground infrastructure, as highways or high speed train lines, imply increasing number of long tunnels and viaducts in mountainous countries. Moreover, for the sake of the environment, only some selected construction methods are eligible for sensitive areas. Among them, a very popular one for medium span concrete viaducts is the span by span construction with movable scaffolding system. The method can be easily adapted to any geometry and, from an environmental point of view, only the shadow of the deck is spoilt during construction periods. Since its first application in the Kettiger Hangbrücke, (Germany) in 1959, this construction method has been applied extensively all around the world. The paper will describe the pros and cons of the method and will explain in detail the last developments made in order to reduce to a minimum the critical path, increasing its competitiveness. New construction sequences, non-standardized structural details, static and dynamic tests, finite element model analysis and recent already built examples will be described to illustrate the possibilities of the method.The author are indebted to the Spanish Ministry of Economy and Competitiveness for the funding provided through the research project BIA2017-86811-C2, funded with FEDER funds. Authors are also indebted to the Secretaria d’ Universitats i Recerca de la Generalitat de Catalunya, Spain, for the funding provided through Agaur (2017 SGR 1481). The author wants to thank also Mr. Roberto Soto, from Mecanotubo S.A., for all his support.Postprint (published version
Advances in Intelligent Sensors and IoT Solutions
No full textTechnological progress has led to the prominence of sensors and the Internet of things (IoT) as crucial components in numerous monitoring environments. Sensors are devices capable of detecting and measuring a variety of phenomena, whether physical, structural, environmental, chemical, or biological. These sensors are supported by the IoT, a network that enables the gathering and sharing of data across connected devices. The integration of sensors with the IoT has driven significant transformations in industries such as healthcare, agriculture, transportation, construction, and urban management by facilitating real-time data collection and analysis. This enhances decision making, increases automation, and boosts efficiency. This Special Issue focuses on sensors and the IoT, publishing a collection of academic articles that explore cutting-edge advancements in areas such as the mechanical characterization of concrete structures, digital twin technologies in Industry 5.0, cloud-based machine learning, the Internet of remote things, and microgrid technologies.Peer ReviewedPostprint (published version
Static structural system identification for beam-like structures using compatibility conditions
No full textThis is the peer reviewed version of the following article: [Lei J, Xu D, Turmo J. Static structural system identification for beam-like structures using compatibility conditions. Struct Control Health Monit. 2018;25:e2062. https://doi.org/10.1002/stc.2062], which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/stc.2062/full. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Due to the inevitable noise existing in the measured responses, structural system identification is often a challenging task in terms of the accuracy of the estimations. Structural system identification by the observability method, which is characterized by the analysis of null spaces, is a powerful tool to determine the observability of structural parameters. However, it did not cope well with measurement errors so far. In this paper, for the first time, functional relations among displacements, denoted by the term compatibility conditions, in beam-like structures are derived by the observability method. Then, compatibility conditions are imposed in an optimization procedure to minimize the discrepancy between the measured response and the compatible one. The compatible response obtained by the optimization is used to obtain the final estimations of the parameters. In a simply supported bridge example, the proposed method is thoroughly evaluated regarding the number of measurements, error levels, and load cases. In an example of a continuous bridge, different load cases are used to estimate the bending stiffnesses of different zones. The accuracy and the efficacy of the proposed method are verified by the numerical results.Peer Reviewe
A comprehensive description of a Low-Cost Angular Data Monitoring System
No full textStructural Health Monitoring (SHM) is basic to survey the exactness of strength forecasts of structures. Utilizing low-cost sensors on structural assessment have increased in contrast with using high-cost sensors. Although these may not be as exact and accurate as of the costly electronic gadgets, with an effective code and right use there is a probability of getting helpful data from them. The information produced from these low-cost sensors can provide useful insight for the SHM systems. In this paper problems regarding angular data acquisition together with their respective solutions are presented. Not only issues regarding coding and placing of these sensors have been presented completely, but precise solutions for the aforementioned problems as well as an efficient way of assembling and preparing the sensors have also been presented. The proposed circuit is composed of an accelerometer, a gyroscope, a magnetometer, an Arduino board and a Laptop, as an information recorder and moderator.The authors are indebted to the Spanish Ministry of Economy and Competitiveness for the funding pro-vided through the research project BIA2017-86811-C2-1-R directed by José Turmo and BIA2017-86811-C2-2-R, directed by Jose Antonio Lozano-Galant. All these projects are funded with FEDER funds. Authors are also indebted to the Secretaria d’ Universitats i Recerca de la Generalitat de Catalunya for the fund-ing provided through Agaur (2017 SGR 1481). It is also to be noted that funding for this research has been provided for MR. SEYEDMILAD KOMARIZA-DEHASL by Agencia Estatal de Investigación del Ministerio de Ciencia Innovación y Universidades grant and the Fondo Social Europeo grant (PRE2018-083238).Postprint (published version
Advances in Intelligent Sensors and IoT Solutions
No full textTechnological progress has led to the prominence of sensors and the Internet of things (IoT) as crucial components in numerous monitoring environments. Sensors are devices capable of detecting and measuring a variety of phenomena, whether physical, structural, environmental, chemical, or biological. These sensors are supported by the IoT, a network that enables the gathering and sharing of data across connected devices. The integration of sensors with the IoT has driven significant transformations in industries such as healthcare, agriculture, transportation, construction, and urban management by facilitating real-time data collection and analysis. This enhances decision making, increases automation, and boosts efficiency. This Special Issue focuses on sensors and the IoT, publishing a collection of academic articles that explore cutting-edge advancements in areas such as the mechanical characterization of concrete structures, digital twin technologies in Industry 5.0, cloud-based machine learning, the Internet of remote things, and microgrid technologies.Peer ReviewedPostprint (published version
Analysis using modal information in SSI by dynamic observability method
No full textStructural Health Monitoring (SHM) has become a powerful tool to help decision making for management of structures along their service life. Estimation of parameters from dynamic response is more appealing than doing it from static response for abundant dynamic database. The aim of this paper is to propose a new dynamic Structural System Identification (SSI) methodology, using subsets of masses, natural frequencies and modal shapes to perform SSI combined with the observability method (OM) and the constrained observability method (COM), for its one-time calculation by solving just one objective function. New algorithms are introduced and one example using experimental data is used as a proof of concept to verify its feasibility. Last, a large structure is used to show the potential of the practical application of the proposed methodology. It turns out with this new methodology, unknown bending stiffness of the structure can be determined efficiently using modal information.Postprint (published version
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