Las estructuras que trabajan por forma se caracterizan por la íntima e indisociable relación entre geometría y comportamiento estructural. Por consiguiente, la elección de una apropiada geometría es el paso previo indispensable en el diseño conceptual de dichas estructuras.
En esa tarea, la selección de las posibles geometrías antifuniculares para las distribuciones de cargas permanentes más habituales son más bien limitadas y, muchas veces, son criterios no estructurales (adaptabilidad funcional, estética, proceso constructivo, etc.) los que no permiten la utilización de dichas geometrías que garantizarían el máximo aprovechamiento del material.
En este contexto, esta investigación estudia la posibilidad de obtener una estructura sin momentos flectores incluso si la geometría no es antifunicular para sus cargas permanentes.
En efecto, este trabajo presenta un procedimiento, basado en la estática gráfica, que demuestra cómo un conjunto de cargas adicionales, introducidas a través de un sistema de pretensado exterior con elementos post-tesos, puede eliminar los momentos flectores debidos a cargas permanentes en cualquier geometría plana. Esto se traduce en una estructura antifunicular que proporciona respuestas innovadoras a demandas conjuntas de versatilidad arquitectónica y optimización del material.
Dicha metodología gráfica ha sido implementada en un software distribuido libremente (EXOEQUILIBRIUM), donde el análisis estructural y la variación geométrica están incluidos en el mismo entorno interactivo y paramétrico. La utilización de estas herramientas permite más versatilidad en la búsqueda de nuevas formas eficientes, lo cual tiene gran importancia en el diseño conceptual de estructuras, liberando al ingeniero de la limitación del propio cálculo y de la incomprensión del comportamiento estructural, facilitando extraordinariamente el hecho creativo a la luz de una metodología de este estilo.
Esta investigación incluye la aplicación de estos procedimientos a estructuras de cualquier geometría y distribución inicial de cargas, así como el estudio de diferentes posibles criterios de diseño para optimizar la posición del sistema de post-tesado. Además, la metodología ha sido empleada en el proyecto de maquetas a escala reducida y en la construcción de un pabellón hecho enteramente de cartón, lo que ha permitido obtener una validación física del procedimiento desarrollado.
En definitiva, esta tesis expande de manera relevante el rango de posibles geometrías antifuniculares y abre enormes posibilidades para el diseño de estructuras que combinan eficiencia estructural y flexibilidad arquitectónica.
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2018
|
Todisco, L; Stocks, E; León, J; Corres, H Enhancing the Structural Performance of Masonry Structures by Post-Tensioning Artículo de revista Nexus Network Journal, pp. 1–21, 2018. Resumen | Enlaces | BibTeX @article{Todisco2018b,
title = {Enhancing the Structural Performance of Masonry Structures by Post-Tensioning},
author = {L Todisco and E Stocks and J León and H Corres},
doi = {10.1007/s00004-018-0374-z},
year = {2018},
date = {2018-01-01},
journal = {Nexus Network Journal},
pages = {1--21},
abstract = {textcopyright 2018 Kim Williams Books, Turin Despite the evident advantages of combining masonry with prestress, their joint use has been poorly exploited during the last decades. This paper claims the high potential of masonry as a primary load-bearing material when combined with post-tensioning. This work deals with arch footbridges and antifunicular structures. With respect to the first, this research illustrates the introduction of external loads by internal post-tensioning to favourably increase the axial forces in a masonry arch, and consequently improving its structural behaviour. With respect to the second, this work shows how bending moments in a non-funicular 2D curved geometry can be eliminated through an external post-tensioning system. In summary, this research strongly expands the range of post-tensioned masonry structures that exhibit a bending-free (or quasi bending-free) behaviour and, de facto, opens up new possibilities for designs that combine structural efficient solutions with traditional materials.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
textcopyright 2018 Kim Williams Books, Turin Despite the evident advantages of combining masonry with prestress, their joint use has been poorly exploited during the last decades. This paper claims the high potential of masonry as a primary load-bearing material when combined with post-tensioning. This work deals with arch footbridges and antifunicular structures. With respect to the first, this research illustrates the introduction of external loads by internal post-tensioning to favourably increase the axial forces in a masonry arch, and consequently improving its structural behaviour. With respect to the second, this work shows how bending moments in a non-funicular 2D curved geometry can be eliminated through an external post-tensioning system. In summary, this research strongly expands the range of post-tensioned masonry structures that exhibit a bending-free (or quasi bending-free) behaviour and, de facto, opens up new possibilities for designs that combine structural efficient solutions with traditional materials. |
2016
|
Todisco, Leonardo; Mueller, Caitlin Externally post-tensioned structures : Validation through physical models Artículo en actas International Conference on Structures and Architecture, pp. 1144–1151, 2016, ISBN: 9781138026513. BibTeX @inproceedings{Todisco2016b,
title = {Externally post-tensioned structures : Validation through physical models},
author = {Leonardo Todisco and Caitlin Mueller},
isbn = {9781138026513},
year = {2016},
date = {2016-01-01},
booktitle = {International Conference on Structures and Architecture},
pages = {1144--1151},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
|
Todisco, Leonardo Funicularity and Equilibrium for High-Performance Conceptual Design Tesis doctoral Technical University of Madrid, Spain, 2016. Enlaces | BibTeX @phdthesis{Todisco2016f,
title = {Funicularity and Equilibrium for High-Performance Conceptual Design},
author = {Leonardo Todisco},
url = {http://oa.upm.es/39733/},
year = {2016},
date = {2016-01-01},
school = {Technical University of Madrid, Spain},
keywords = {},
pubstate = {published},
tppubtype = {phdthesis}
}
|
Todisco, Leonardo; Corres-Peiretti, Hugo; Mueller, Caitlin Funicularity through External Posttensioning : Design Philosophy and Computational Tool Artículo de revista Journal of Structural Engineering, 142 (2), pp. 1–9, 2016, ISSN: 978-90-5363-042-6. Enlaces | BibTeX @article{Todisco2016e,
title = {Funicularity through External Posttensioning : Design Philosophy and Computational Tool},
author = {Leonardo Todisco and Hugo Corres-Peiretti and Caitlin Mueller},
doi = {10.1061/(ASCE)ST.1943-541X.0001416.},
issn = {978-90-5363-042-6},
year = {2016},
date = {2016-01-01},
journal = {Journal of Structural Engineering},
volume = {142},
number = {2},
pages = {1--9},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
2015
|
Todisco, L; Fivet, C; Corres-Peiretti, H; Mueller, C Design and exploration of externally posttensioned structures using graphic statics Artículo de revista Journal of the International Association for Shell and Spatial Structures, 56 (4), pp. 249–258, 2015. Resumen | BibTeX @article{Todisco2015b,
title = {Design and exploration of externally posttensioned structures using graphic statics},
author = {L Todisco and C Fivet and H Corres-Peiretti and C Mueller},
year = {2015},
date = {2015-01-01},
journal = {Journal of the International Association for Shell and Spatial Structures},
volume = {56},
number = {4},
pages = {249--258},
abstract = {textcopyright Copyright 2015 by Leonardo Todisco, Corentin Fivet, Hugo Corres-Peiretti and Caitlin Mueller. Funicular structures, which follow the shapes of hanging chains, work in pure tension (cables) or pure compression (arches), and offer a materially efficient solution compared to structures that work through bending action. However, the set of geometries that are funicular under common loading conditions is limited. Nonstructural design criteria, such as function, program, and aesthetics, often prohibit the selection of purely funicular shapes, resulting in large bending moments and excess material usage. In response to this issue, this paper explores the use of a new design approach that converts non-funicular planar curves into funicular shapes without changing the geometry; instead, funicularity is achieved through the introduction of new loads using external post-tensioning. The methodology is based on graphic statics, and is generalized for any twodimensional shape. The problem is indeterminate, meaning that a large range of allowable solutions is possible for one initial geometry. Each solution within this range results in different internal force distributions and horizontal reactions. The method has been implemented in an interactive parametric design environment, empowering fast exploration of diverse axial-only solutions. In addition to presenting the approach and tool, this paper provides a series of case studies and numerical comparisons between new post-tensioned structures and classical bending solutions, demonstrating that significant material can be saved without compromising on geometrical requirements.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
textcopyright Copyright 2015 by Leonardo Todisco, Corentin Fivet, Hugo Corres-Peiretti and Caitlin Mueller. Funicular structures, which follow the shapes of hanging chains, work in pure tension (cables) or pure compression (arches), and offer a materially efficient solution compared to structures that work through bending action. However, the set of geometries that are funicular under common loading conditions is limited. Nonstructural design criteria, such as function, program, and aesthetics, often prohibit the selection of purely funicular shapes, resulting in large bending moments and excess material usage. In response to this issue, this paper explores the use of a new design approach that converts non-funicular planar curves into funicular shapes without changing the geometry; instead, funicularity is achieved through the introduction of new loads using external post-tensioning. The methodology is based on graphic statics, and is generalized for any twodimensional shape. The problem is indeterminate, meaning that a large range of allowable solutions is possible for one initial geometry. Each solution within this range results in different internal force distributions and horizontal reactions. The method has been implemented in an interactive parametric design environment, empowering fast exploration of diverse axial-only solutions. In addition to presenting the approach and tool, this paper provides a series of case studies and numerical comparisons between new post-tensioned structures and classical bending solutions, demonstrating that significant material can be saved without compromising on geometrical requirements. |
