Optimization of reinforced concrete building frames with automated grouping of columns

[EN] In structural design, it is common practice to adopt the same cross-section dimensions for a group of elements. This procedure is mainly for practical and aesthetic reasons, as well as to reduce labour costs, but it also has a positive effect of reducing the number of variables, which simplifies the usual trial and error design process. On the other hand, the total materials cost obtained is closely related to this grouping. Based on this, the present work aims to minimize the cost of reinforced concrete plane frames considering the automated grouping of columns. To achieve this objective, an optimization software was developed by the association of matrix structural analysis, dimensioning and optimization. The sections dimensions, the area of steel and the concrete strength of beams and columns were taken as design variables. For a given maximum number of groups, the optimum grouping and the corresponding values to design variables are obtained. The strategy proposed in this paper to obtain the grouping reduces significantly the number of infeasible candidate solutions during the search process and avoid the proposition of unrealistic designs. For the optimization, a variant of the Harmony Search method was adopted. Some structures were analyzed in order to validate the application of the proposed formulation, as well as to verify the influence of the grouping of elements on the final results. In these structures, it was possible to observe a significant additional reduction in the total cost when automated grouping is performed regarding a uniform grouping, even when a small number of groups is considered. For the 20-floor building frame analyzed, the cost reduction from uniform to automated grouping varied from 5.53 to 7.35%. The influence of the concrete strength on optimal results was also investigated, indicating a cost reduction of 9.74% from best (40 MPa) to worst case (20 MPa). In general, it can be concluded that, when applied in conjunction with the usual design variables, the proposed procedure can enable a significant additional economy, without affecting the structural safety.The authors acknowledge the financial support of the Brazilian Council for Scientific and Technological Development CNPq (Grant: 302736/2017-4) and of the Spanish Ministry of Economy and Competitiveness, along with FEDER funding (Project: BIA2017-85098-R).Boscardin, J.; Yepes, V.; Kripka, M. (2019). Optimization of reinforced concrete building frames with automated grouping of columns. Automation in Construction. 104:331-340. https://doi.org/10.1016/j.autcon.2019.04.024S33134010

Optimization of prestressed concrete road bridges by the response surface methodology

[ES] Los puentes son infraestructuras esenciales para mejorar la comunicación dentro de un territorio. La optimización constituye un proceso que permite obtener puentes de menor coste bajo ciertas restricciones. Debido a la complejidad de los problemas estructurales, la optimización matemática no es útil y se recurre a la optimización heurística debido a su mayor eficacia. En este trabajo se presenta una alternativa a la optimización heurística basada en los metamodelos. El procedimiento consiste en una reducción de los factores iniciales mediante el diseño de experimentos, reduciendo significativamente la complejidad del problema sin perder información. Posteriormente, se aplica la metodología de la superficie de respuesta para obtener el óptimo del problema. Este procedimiento se aplica a un tablero de un puente de losa maciza que cumpla todas las restricciones de las normativas.[EN] Bridges are essential infrastructures to improve communication in a region. Optimization is a process that can be used to obtain cheaper bridges under certain restrictions. Due to the complexity of the structural problems, mathematical optimization is not useful and heuristic optimization is used due its greater efficiency. This work presents an alternative to heuristic optimization based on metamodels. The process consists of reducing the initial factors by design of experiments, which significantly reduces the complexity of the problem without losing information. Then, response surface methodology is applied to obtain the optimum of the problem. This process is applied to a solid slab bridge deck that accomplish with all regulatory restrictions.Los autores agradecen la financiación del Ministerio de Economía y Competitividad, junto con los fondos FEDER (Proyecto: BIA2017-85098-R) y del Consejo Nacional de Desarrollo Científico y Tecnológico CNPq/Brasil (Proc. 302736/2017-4).Penadés-Plà, V.; Yepes, V.; Kripka, M. (2019). Optimización de puentes pretensados mediante la metodología de la superficie de respuesta. Revista CIATEC-UPF. 11(2):22-35. https://doi.org/10.5335/ciatec.v11i2.9159S223511