Motion-Based Design of Passive Damping Devices to Mitigate Wind-Induced Vibrations in Stay Cables

Wind action can induce large amplitude vibrations in the stay cables of bridges. To reduce the vibration level of these structural elements, different types of passive damping devices are usually installed. In this paper, a motion-based design method is proposed and implemented in order to achieve the optimum design of different passive damping devices for stay cables under wind action. According to this method, the design problem is transformed into an optimization problem. Thus, its main aim is to minimize the different terms of a multi-objective function, considering as design variables the characteristic parameters of each considered passive damping device. The multi-objective function is defined in terms of the scaled characteristic parameters, one single-function for each parameter, and an additional function that checks the compliance of the considered design criterion. Genetic algorithms are considered as a global optimization method. Three passive damping devices have been studied herein: viscous, elastomeric and friction dampers. As a benchmark structure, the Alamillo bridge (Seville, Spain), is considered in order to validate the performance of the proposed method. Finally, the parameters of the damping devices designed according to this proposal are successfully compared with the results provided by a conventional design method

Who leads Research Productivity Change? Guidelines for R&D policy makers

Relying on efficiency analysis we evaluate to what extent policy makers have been able to promote the establishment of consolidated and comprehensive research groups to contribute to the implementation of a successful innovation system for the Spanish food technology sector, oriented to the production of knowledge based on an application model. Using data envelopment analysis techniques and Malmquist productivity indices we find pervasive levels of inefficiency and a typology of different research strategies. Among these, in contrast to what has been assumed, established groups do not play the pre-eminent benchmarking role; rather, partially oriented, specialized and "shooting star" groups are the most common patterns. These results correspond with an infant innovation system, where the fostering of higher levels of efficiency and promotion of the desired research patterns are ongoing.Innovation Policy; Management; Productivity Change; Malmquist Index; Distance Function

La incorporación de la innovación y el emprendedurismo en la Educación Superior: una formación de futuro

Trabajo presentado al V Congreso Iberoamericano de Docencia Universitaria celebrado en Valencia (España) del 29 al 31 de Octubre de 2008.Actualmente, el papel de las universidades va más allá de las actividades de enseñanza e investigación. Cada vez más la sociedad demanda de éstas una mayor implicación en el proceso de desarrollo económico y social del territorio. La universidad emprendedora requiere de un rediseño de su estrategia global, de modo que ésta le permita cumplir con los retos impuestos por su nuevo papel en la sociedad. En el presente trabajo se pretende poner de manifiesto, en primer lugar, las implicaciones que la consideración de “Universidad Emprendedora” tiene para la actividad docente. Para ello se tratará el tema de la incorporación de módulos formativos sobre innovación y emprendedurismo en la educación superior, así como los objetivos que persigue y el proceso que se debería seguir para su implantación. Adicionalmente se exponen algunas iniciativas de éxito, tanto nacionales como internacionales, en la incorporación de módulos sobre innovación y emprendedurismo en la educación superior. Para finalizar se expondrán conclusiones y recomendaciones para la implantación de dichos módulos formativos.Peer reviewe

A crowd-structure interaction model to analyze the lateral lock-in phenomenon on footbridges

In this paper a simplified biomechanical crowd-structure interaction model is proposed and validated in order to analyse the lateral lock-in phenomenon on real footbridges. The proposed crowd-structure interaction model is organized in three levels: (i) pedestrian-structure interaction; (ii) interaction among pedestrians in the crowd; and (iii) interaction between the crowd and the structure. To this end, first, the human-structure interaction of each pedestrian is modelled via a simplified two degrees of freedom system. Second, the interaction among pedestrians inside the crowd is simulated using a multi-agent model. The considered model simulates the movement of each pedestrian from the dynamic equilibrium of the different social forces that act on him/her. Finally, the crowd-structure interaction is achieved modifying the behaviour of the pedestrians depending on the comfort level experienced. For this purpose, the recommendations established by the French standards have been considered. The integration of the three levels in an overall model is achieved by the implementation of a predictive– corrective method. The performance of the proposed model is validated correlating the numerical and experimental dynamic response of the Pedro e Inês footbridge during the development of a lateral lock-in pedestrian test. As the first lateral natural frequency of the footbridge is inside the range that characterizes the walking pedestrian step frequency in lateral direction, numerical and experimental studies were performed to analyse its behaviour under pedestrian action. The agreement between the numerical and experimental results is adequate. However, further studies are recommended in order to generalize the proposed approach and facilitate its use during the design project of future footbridges.Ministerio de Ciencia DPI2014-53947-

Recent Advances in the Serviceability Assessment of Footbridges Under Pedestrian-Induced Vibrations

Current international guidelines determine the effect of pedestrians on footbridges via an equivalent harmonic load. However, the dynamic response of footbridges obtained according to these standards differs from the values recorded experimentally. In order to overcome this issue, a new modelling framework has been recently proposed by several researchers. This novel approach allows considering more accurately three key aspects: (i) the inter- and intra-subject variability, (ii) the pedestrian-structure interaction and (iii) the crowd dynamics. For this purpose, different crowd-structure interaction models have been developed. Despite the large number of proposals, all of them share the same scheme: the crowd-structure interaction is simulated by linking two sub-models, namely (i) a pedestrian-structure interaction sub-model and (ii) a crowd sub-model. Furthermore, the variability of the pedestrian’s behaviour may be taken into account via the assumption that the model parameters are random variables. In this chapter, a summary of the state-of-art of this new modelling framework is presented, with special emphasis in a case study where the crowd-structure interaction model developed by the authors is used to simulate the lateral lock-in phenomenon on a real footbridge

Modelo OIT para la innovación tecnológica de los procesos de empresa

El "groupware" es la parte de la tecnología ofimática que soporta el trabajo en grupo. Abarca un amplio conjunto de tecnologías hardware y software y de aplicaciones tales como sistemas de mensajería,sistemas grupales de apoyo a las decisiones, redes de conversaciones y de flujos de trabajo, bases de datos compartidas, y un largo etcétera, que le confieren un gran potencial de cambio organizativo y empresarial. Entre otras consecuencias, propicia nuevos tipos de organización, como las organizaciones reticulares ("networked organizations"), nuevas relaciones sociales y laborales, y contribuye a generar nuevas oportunidades y procesos de negocios. Clasificamos al groupware como una tecnología socio técnica, por lo que su implantación en la empresa y su integración en el diseño de procesos de negocios requiere los cuidados propios del diseño socio técnico. En este trabajo, se enfoca la innovación tecnológica con groupware derivándola de un modelo general de innovación empresarial en el campo de las tecnologías de la información, que considera simultáneamente a los procesos de negocio en solidaridad circular activa con una. dinámica convergente de tres áreas: O (Organización), ¡(Individuos, o factor humano de la empresa) y T (Tecnología). Desde una teoría ofimática respetuosa con el modelo OIT llegamos finalmente a un procedimiento cíclico de transferencia de la tecnología groupware

Estimating robust optimum parameters of tuned mass dampers using multiobjective genetic algorithms

Congreso celebrado en la Escuela de Arquitectura de la Universidad de Sevilla desde el 24 hasta el 26 de junio de 2015.Tuned mass dampers (TMD) are a well-known control device widely used to control the vibratory problem originated by the pedestrian action on footbridges. The main purpose of this study is the robust multi-objective optimization design of a TMD using genetic algorithms to control the structural vibrations of a footbridge due to the pedestrian action. The performance of the TMD has been improved designing optimally its parameters, including, mass, stiffness and damping ratio using multiobjective genetic algorithms. Moreover, in order to take into account the uncertainties existing in the system, a robust design optimization procedure has been performed. As an example, a slender steel footbridge, modelled by 3-D frame elements, is used to assess numerically the performance and accuracy of the proposed method. The pedestrian action has been simulated by an equivalent harmonic force. The proposed approach is compared with the classical Den Hartog's proposal. This comparison shows that this approach is more effective than the classica l reported method and more feasible due to the smaller TMD parameters

Effect of Vinyl Flooring on the Modal Properties of a Steel Footbridge

Damping ratios associated with non structural elements play an important role in mitigating the pedestrian-induced vibrations of slender footbridges. In particular, this paper analyses the effect of vinyl flooring on the modal parameters of steel footbridges. Motivated by the unexpected high experimental damping ratios of the first vibration modes of a real footbridge, whose deck was covered by a vinyl flooring, this paper aims at assessing more accurately the experimental damping ratios generated by this non-structural element on steel footbridges. For this purpose, a laboratory footbridge was built and vinyl flooring was installed on it. Its numerical and experimental modal parameters without and with the vinyl flooring were determined. The operational modal analysis method was used to estimate experimentally the modal parameters of the structure. The damping ratios associated with the vinyl flooring were obtained via the substraction between the experimental damping ratios of the laboratory footbridge with and without the vinyl flooring. An average increase of the damping ratios of 2.069% was observed due to the vinyl flooring installed. According to this result, this type of pavement may be a useful tool to significantly increase the damping ratios of steel footbridges in order to reduce pedestrian-induced vibrationsMinisterio de Economía y Competitividad DPI2014-53947-RFondo Europeo de Desarrollo Regional DPI2014-53947-

An in-depth analysis of a TTO's objectives alignment within the university strategy: An ANP-based approach

[EN] This paper presents the application of the Analytic Network Process for the analysis of the contribution of the third mission action plans to the research transfer policies set by the University Governing Body. The model is applied to the case study of the Technology Transfer Offices (TTO) of the Universitat Politècnica de València (Spain). The paper develops a rigorous decision-making tool that helps TTO managers analyse the effectiveness of TTO activities and their degree of alignment with the institution¿s objectives. This work considers TTO managers¿ qualitative information and value judgments about the activities performed.This work has been funded by Universitat Politecnica de Valencia PAID-06-2011/2042. The translation of this paper has been funded by the Universitat Politecnica de Valencia.Aragonés-Beltrán, P.; Poveda Bautista, R.; Jiménez-Sáez, F. (2017). An in-depth analysis of a TTO's objectives alignment within the university strategy: An ANP-based approach. Journal of Engineering and Technology Management. 44:19-43. doi:10.1016/j.jengtecman.2017.03.002S19434

Science and technology policies: A tale of political use, misuse and abuse of traditional R&D indicators

Future political priorities for science and technology (S&T) policy formulation usually rest on a rather simplistic interpretation of past events. This can lead to serious errors and distortions and can negatively affect the innovation system. In this article we try to highlight the riskiness involved in policy making based on traditional R&D indicators and trends. We would emphasise that this approach does not take account of structural aspects crucial for the analysis of the innovation system. We examine the implications for science, technical and human resources policies of the political challenge of R&D convergence in a peripheral EU region. Three scenarios are developed based on application of the same criteria to the trends observed in traditional R&D input indicators