Etiqueta: safety

Redes neuronales aplicadas al diseño multiobjetivo de puentes postesados

Nos acaban de publicar en línea en la revista Structural and Multidisciplinary Optimization (revista indexada en JCR en el primer cuartil) un trabajo de investigación en el que utilizamos las redes neuronales artificiales junto para el diseño multiobjetivo de puentes postesados de carreteras. Os paso a continuación el resumen y el enlace al artículo por si os resulta de interés. El enlace del artículo es el siguiente: http://link.springer.com/article/10.1007%2Fs00158-017-1653-0

Referencia:

García-Segura, T.; Yepes, V.; Frangopol, D.M. (2017). Multi-objective design of post-tensioned concrete road bridges using artificial neural networks. Structural and Multidisciplinary Optimization, doi:10.1007/s00158-017-1653-0

Abstract:

In order to minimize the total expected cost, bridges have to be designed for safety and durability. This paper considers the cost, the safety, and the corrosion initiation time to design post-tensioned concrete box-girder road bridges. The deck is modeled by finite elements based on problem variables such as the cross-section geometry, the concrete grade, and the reinforcing and post-tensioning steel. An integrated multi-objective harmony search with artificial neural networks (ANNs) is proposed to reduce the high computing time required for the finite-element analysis and the increment in conflicting objectives. ANNs are trained through the results of previous bridge performance evaluations. Then, ANNs are used to evaluate the constraints and provide a direction towards the Pareto front. Finally, exact methods actualize and improve the Pareto set. The results show that the harmony search parameters should be progressively changed in a diversification-intensification strategy. This methodology provides trade-off solutions that are the cheapest ones for the safety and durability levels considered. Therefore, it is possible to choose an alternative that can be easily adjusted to each need.

Keywords:

Multi-objective harmony search; Artificial neural networks; Post-tensioned concrete bridges; Durability; Safety.

Os dejo a continuación la versión autor del artículo.

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Multiobjective optimization of post-tensioned concrete box-girder road bridges considering cost, CO2 emissions, and safety

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http://authors.elsevier.com/a/1TROAW4G4Bhqk

Abstract: This paper presents a multiobjective optimization of post-tensioned concrete road bridges in terms of cost, CO2 emissions, and overall safety factor. A computer tool links the optimization modulus with a set of modules for the finite-element analysis and limit states verification. This is applied for the case study of a three-span continuous post-tensioned box-girder road bridge, located in a coastal region. A multiobjective harmony search is used to automatically search a set of optimum structural solutions regarding the geometry, concrete strength, reinforcing and post-tensioned steel. Diversification strategies are combined with intensification strategies to improve solution quality. Results indicate that cost and CO2 emissions are close to each other for any safety range. A one-euro reduction, involves a 2.34 kg CO2 emissions reduction. Output identifies the best variables to improve safety and the critical limit states. This tool also provides bridge managers with a set of trade-off optimum solutions, which balance their preferences most closely, and meet the requirements previously defined.

Keywords

  • Multiobjective optimization;
  • CO2 emissions;
  • Safety;
  • Post-tensioned concrete;
  • Box-girder bridge;
  • Multiobjective harmony search

Highlights

  • A multiobjective optimization of post-tensioned concrete road bridges is presented.
  • A computer tool combines finite-element analysis and limit states verification.
  • Output provides a trade-off between cost, CO2 emissions, and overall safety factor.
  • Near the optima, a one-euro reduction represents a 2.34 kg CO2 emissions reduction.
  • Results show the cheapest and most eco-friendly variables for improving safety.

Reference:

GARCÍA-SEGURA, T.; YEPES, V. (2016). Multiobjective optimization of post-tensioned concrete box-girder road bridges considering cost, CO2 emissions, and safety. Engineering Structures, 125:325-336. DOI: 10.1016/j.engstruct.2016.07.012.