Pub Date : 2021-01-01DOI: 10.20898/J.IASS.2021.002
E. M. Segal, Albert Chao, Lisa Ramsburg, P. Draper
Location of Project: Barcelona, Spain Structural Type:thin shell roofProject Scale:1.9 m by 3.55 m in planArchitect:Lisa Ramsburg and Albert ChaoStructural Engineer:Edward M. Segal and Powell DraperConstruction year:2019
项目地点:西班牙巴塞罗那结构类型:薄壳屋顶项目规模:1.9米× 3.55米平面建筑师:Lisa Ramsburg和Albert chao结构工程师:Edward m . Segal和Powell DraperConstruction时间:2019
{"title":"A Pavilion Made from Scrap Acrylic and Physically Form-Found at Full Scale","authors":"E. M. Segal, Albert Chao, Lisa Ramsburg, P. Draper","doi":"10.20898/J.IASS.2021.002","DOIUrl":"https://doi.org/10.20898/J.IASS.2021.002","url":null,"abstract":"Location of Project: Barcelona, Spain Structural Type:thin shell roofProject Scale:1.9 m by 3.55 m in planArchitect:Lisa Ramsburg and Albert ChaoStructural Engineer:Edward M. Segal and Powell DraperConstruction year:2019","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81829919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.20898/J.IASS.2020.012
Diego Rivera, Renaud Danhaive, C. Mueller
This research outlines a new computational workflow for the design and optimization of patterned, perforated surface structures. Well-designed surface structures can be highly efficient on their own, but their potential for structural efficiency can be notably improved by deliberately introducing specific aperture patterns. Patterned surfaces can also be used to produce more stimulating architectural environments, and even those of increasing complexity can be realized thanks to recent developments in digital fabrication. With this said, designers currently lack a streamlined and rigorous approach for the exploration of patterned surface structures. This research aims to address this issue by advancing a recent work that employs NURBS-based isogeometric analysis to integrate structural analysis into an accessible CAD modeling platform. Specifically, this paper proposes an adaptive pattern optimization framework formulated to save designers appreciable computational time. Not only does this framework offer a way to quickly visualize various design solutions, but it also provides the designer an important opportunity for design interaction and control over design evolution, in turn lending itself as a versatile tool for the exploration and conceptual design of patterned surface structures.
{"title":"Adaptive Framework for Structural Pattern Optimization","authors":"Diego Rivera, Renaud Danhaive, C. Mueller","doi":"10.20898/J.IASS.2020.012","DOIUrl":"https://doi.org/10.20898/J.IASS.2020.012","url":null,"abstract":"This research outlines a new computational workflow for the design and optimization of patterned, perforated surface structures. Well-designed surface structures can be highly efficient on their own, but their potential for structural efficiency can be notably improved by deliberately\u0000 introducing specific aperture patterns. Patterned surfaces can also be used to produce more stimulating architectural environments, and even those of increasing complexity can be realized thanks to recent developments in digital fabrication. With this said, designers currently lack a streamlined\u0000 and rigorous approach for the exploration of patterned surface structures. This research aims to address this issue by advancing a recent work that employs NURBS-based isogeometric analysis to integrate structural analysis into an accessible CAD modeling platform. Specifically, this paper\u0000 proposes an adaptive pattern optimization framework formulated to save designers appreciable computational time. Not only does this framework offer a way to quickly visualize various design solutions, but it also provides the designer an important opportunity for design interaction and control\u0000 over design evolution, in turn lending itself as a versatile tool for the exploration and conceptual design of patterned surface structures.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79121375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.20898/J.IASS.2020.010
Y. Sakai, M. Ohsaki
This paper presents a design method of Auxetic Bending-Active Gridshells (ABAGs), which are curved surfaces generated from the initial flat grid with 2-dimensional auxetic patterns. One of the mechanical properties of ABAGs is that a dome-like shape of a curved surface can be easily obtained by bending a grid due to negative Poisson's ratio for in-plane deformation. Shapes of auxetic patterns are relevant to Poisson's ratio. Non-periodic and/or hybrid 2-dimensional auxetic patterns are developed for designing the initial flat grid of ABAGs. Shape parameters are the sizes of each plane unit for tuning its reentrant pattern, and two types of reentrant shapes are mixed on an initial flat grid. Using the non-uniform patterns, we can obtain an asymmetric and more complex free-form surface of ABAGs than those composed of a uniform reentrant pattern. Discrete Gaussian curvature at each node on a curved surface is computed for quantitatively evaluating the properties of shapes of the obtained surfaces. Possibility of ABAGs as a new design tool is demonstrated by showing that various shapes are generated through large deformation analysis with the forced displacements at the supports.
{"title":"Parametric Study of Non-periodic and Hybrid Auxetic Bending-Active Gridshells","authors":"Y. Sakai, M. Ohsaki","doi":"10.20898/J.IASS.2020.010","DOIUrl":"https://doi.org/10.20898/J.IASS.2020.010","url":null,"abstract":"This paper presents a design method of Auxetic Bending-Active Gridshells (ABAGs), which are curved surfaces generated from the initial flat grid with 2-dimensional auxetic patterns. One of the mechanical properties of ABAGs is that a dome-like shape of a curved surface can be easily\u0000 obtained by bending a grid due to negative Poisson's ratio for in-plane deformation. Shapes of auxetic patterns are relevant to Poisson's ratio. Non-periodic and/or hybrid 2-dimensional auxetic patterns are developed for designing the initial flat grid of ABAGs. Shape parameters are the sizes\u0000 of each plane unit for tuning its reentrant pattern, and two types of reentrant shapes are mixed on an initial flat grid. Using the non-uniform patterns, we can obtain an asymmetric and more complex free-form surface of ABAGs than those composed of a uniform reentrant pattern. Discrete Gaussian\u0000 curvature at each node on a curved surface is computed for quantitatively evaluating the properties of shapes of the obtained surfaces. Possibility of ABAGs as a new design tool is demonstrated by showing that various shapes are generated through large deformation analysis with the forced\u0000 displacements at the supports.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77540694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.20898/J.IASS.2020.008
N. Montagné, C. Douthe, X. Tellier, C. Fivet, O. Baverel
The design of envelopes with complex geometries often leads to construction challenges. To overcome these difficulties, resorting to discrete differential geometry proved successful by establishing close links between mesh properties and the existence of good fabrication, assembling and mechanical properties. In this paper, the design of a special family of structures, called geodesic shells, is addressed using Voss nets, a family of discrete surfaces. The use of discrete Voss surfaces ensures that the structure can be built from simply connected, initially straight laths, and covered with flat panels. These advantageous constructive properties arise from the existence of a conjugate network of geodesic curves on the underlying smooth surface. Here, a review of Voss nets is presented and particular attention is given to the projection of normal vectors on the unit sphere. This projection, called Gauss map, creates a dual net which unveils the remarkable characteristics of Voss nets. Then, based on the previous study, two generation methods are introduced. One enables the exploration and the deformation of Voss nets while the second provides a more direct computational technique. The application of theses methodologies is discussed alongside formal examples.
{"title":"Voss Surfaces: A Design Space for Geodesic Gridshells","authors":"N. Montagné, C. Douthe, X. Tellier, C. Fivet, O. Baverel","doi":"10.20898/J.IASS.2020.008","DOIUrl":"https://doi.org/10.20898/J.IASS.2020.008","url":null,"abstract":"The design of envelopes with complex geometries often leads to construction challenges. To overcome these difficulties, resorting to discrete differential geometry proved successful by establishing close links between mesh properties and the existence of good fabrication, assembling\u0000 and mechanical properties. In this paper, the design of a special family of structures, called geodesic shells, is addressed using Voss nets, a family of discrete surfaces. The use of discrete Voss surfaces ensures that the structure can be built from simply connected, initially straight laths,\u0000 and covered with flat panels. These advantageous constructive properties arise from the existence of a conjugate network of geodesic curves on the underlying smooth surface. Here, a review of Voss nets is presented and particular attention is given to the projection of normal vectors on the\u0000 unit sphere. This projection, called Gauss map, creates a dual net which unveils the remarkable characteristics of Voss nets. Then, based on the previous study, two generation methods are introduced. One enables the exploration and the deformation of Voss nets while the second provides a more\u0000 direct computational technique. The application of theses methodologies is discussed alongside formal examples.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80552419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.20898/J.IASS.2020.011
A. McRobie, Cameron Millar, W. Baker
Graphic statics has been used for over 150 years, having been pioneered by the likes of Maxwell, Cremona, Culmann and Rankine, and has recently seen a resurgence in popularity because of its use in design. However, it is only concerned with equilibrium; as any engineer will testify, whilst equilibrium is necessary, it is not sufficient and stability must also be obtained. This paper develops a novel graphical method for determining the stability and stiffness of prestressable structures. By considering the weighted sum of the Maxwell-Minkowski diagram, the stiffness and stability of the structural mechanisms can be determined. This work extends to cover structures with multiple mechanisms and has been compared to results obtained through experimentation and the finite element method. Furthermore, it extends the work on stiffness to provide a graphical method to estimate the natural frequency of a truss. Whilst this method accurately determines the stiffness of structures, it represents a significant development in the field of graphic statics as it allows an engineer to 'eye-ball' the stability of a given truss. Engineers can also manipulate the form and force diagrams, as desired, to adjust the stiffness of their structure accordingly, whilst being able to visualise the process. Much of the previous work in this area relies heavily upon large matrices, while this method allows a more intimate and hands-on alternative.
{"title":"A Graphical Method for Determining Truss Stability","authors":"A. McRobie, Cameron Millar, W. Baker","doi":"10.20898/J.IASS.2020.011","DOIUrl":"https://doi.org/10.20898/J.IASS.2020.011","url":null,"abstract":"Graphic statics has been used for over 150 years, having been pioneered by the likes of Maxwell, Cremona, Culmann and Rankine, and has recently seen a resurgence in popularity because of its use in design. However, it is only concerned with equilibrium; as any engineer will testify,\u0000 whilst equilibrium is necessary, it is not sufficient and stability must also be obtained. This paper develops a novel graphical method for determining the stability and stiffness of prestressable structures. By considering the weighted sum of the Maxwell-Minkowski diagram, the stiffness and\u0000 stability of the structural mechanisms can be determined. This work extends to cover structures with multiple mechanisms and has been compared to results obtained through experimentation and the finite element method. Furthermore, it extends the work on stiffness to provide a graphical method\u0000 to estimate the natural frequency of a truss. Whilst this method accurately determines the stiffness of structures, it represents a significant development in the field of graphic statics as it allows an engineer to 'eye-ball' the stability of a given truss. Engineers can also manipulate the\u0000 form and force diagrams, as desired, to adjust the stiffness of their structure accordingly, whilst being able to visualise the process. Much of the previous work in this area relies heavily upon large matrices, while this method allows a more intimate and hands-on alternative.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77267312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.20898/J.IASS.2020.009
L.I.W. Arnouts, T. Massart, N. D. Temmerman, P. Berke
Bistable scissor structures, consisting of beams connected by hinges, are transportable and can be transformed from a compact to a deployed configuration. Geometric incompatibilities can be introduced during transformation to obtain a bistable structural response which enforces some instantaneous structural stability in the deployed state. The design of bistable scissor structures requires assessing both the non-linear transformation behaviour, as well as the service state, since a proper structural design has to provide stiffness in the deployed state as well as flexibility during transformation. These contradicting requirements were formulated previously in Arnouts et al. [1] as a multi-objective shape and sizing optimisation (SSO). The originality of this contribution is the elaboration of a design methodology coupling a novel topology optimisation (TO) to SSO and demonstrating its performance for the design of a bistable deployable wall. In this novel step, the number of bistable deployable modules (BDM) of the structure is optimised at low computational cost by finding the location of BDM, yielding mixed structures composed of BDM and non-bistable modules (NBDM) of lower weight and complexity than structures entirely built from BDM. TO is incorporated and assessed in the design methodology prior or subsequent to the SSO step. It is shown that the mixed structures combining BDM and NBDM resulting from the new coupled TO-SSO approach outperform pure BDM based structures.
{"title":"Coupled Sizing, Shape and Topology Optimisation of Bistable Deployable Structures","authors":"L.I.W. Arnouts, T. Massart, N. D. Temmerman, P. Berke","doi":"10.20898/J.IASS.2020.009","DOIUrl":"https://doi.org/10.20898/J.IASS.2020.009","url":null,"abstract":"Bistable scissor structures, consisting of beams connected by hinges, are transportable and can be transformed from a compact to a deployed configuration. Geometric incompatibilities can be introduced during transformation to obtain a bistable structural response which enforces some\u0000 instantaneous structural stability in the deployed state. The design of bistable scissor structures requires assessing both the non-linear transformation behaviour, as well as the service state, since a proper structural design has to provide stiffness in the deployed state as well as flexibility\u0000 during transformation. These contradicting requirements were formulated previously in Arnouts et al. [1] as a multi-objective shape and sizing optimisation (SSO). The originality of this contribution is the elaboration of a design methodology coupling a novel topology optimisation (TO) to\u0000 SSO and demonstrating its performance for the design of a bistable deployable wall. In this novel step, the number of bistable deployable modules (BDM) of the structure is optimised at low computational cost by finding the location of BDM, yielding mixed structures composed of BDM and non-bistable\u0000 modules (NBDM) of lower weight and complexity than structures entirely built from BDM. TO is incorporated and assessed in the design methodology prior or subsequent to the SSO step. It is shown that the mixed structures combining BDM and NBDM resulting from the new coupled TO-SSO approach\u0000 outperform pure BDM based structures.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46014705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.20898/J.IASS.2020.007
Jack Lehrecke, Juan Pablo Osman-Letelier, M. Schlaich
The implementation of post-tensioned elements in concrete structures offers a multitude of benefits with regards to the overall structural behavior, with the efficacy of the applied tendons depending heavily on their geometry. However, the derivation of an optimal tendon geometry for a given structure is nontrivial, requiring engineering experience or the use of complex and often computationally demanding methodologies, e.g.the use of topology optimization strategies. This paper aims to investigate the possibility for optimizing tendon geometries using a path integral based objective function developed at the TU Berlin. For this purpose, the mathematical background is first presented to illustrate the proposed concept. Beginning with a tendon geometry optimization of a simply supported beam and progressing to more complex systems, a generalized approach for doubly curved spatial structures will be presented.
{"title":"Tendon Geometry Optimization Using Path Integrals","authors":"Jack Lehrecke, Juan Pablo Osman-Letelier, M. Schlaich","doi":"10.20898/J.IASS.2020.007","DOIUrl":"https://doi.org/10.20898/J.IASS.2020.007","url":null,"abstract":"The implementation of post-tensioned elements in concrete structures offers a multitude of benefits with regards to the overall structural behavior, with the efficacy of the applied tendons depending heavily on their geometry. However, the derivation of an optimal tendon geometry for\u0000 a given structure is nontrivial, requiring engineering experience or the use of complex and often computationally demanding methodologies, e.g.the use of topology optimization strategies. This paper aims to investigate the possibility for optimizing tendon geometries using a path integral\u0000 based objective function developed at the TU Berlin. For this purpose, the mathematical background is first presented to illustrate the proposed concept. Beginning with a tendon geometry optimization of a simply supported beam and progressing to more complex systems, a generalized approach\u0000 for doubly curved spatial structures will be presented.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78668472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.20898/j.iass.2020.002
Lyubomir A. Zdravkov
To ensure unloading of the whole amount of stored product by gravity, the steel silos are often placed on supporting frame structure. The values of stresses in the joints between the thin shell and supporting frame elements are extremely high. It can cause local loss of stability in the shell. To prevent it, many designers place stiffening elements above the supports. Here the question is how high should be the stiffening elements? The appropriate solution is that they should rise to that level till which the values of meridional normal stresses above the supports and in the middle between them are equalized. But where is this level? Many researchers worked on values and ways of distribution of normal meridional stresses above the supports of the cylindrical shells. As a result of their efforts are determined critical height Hcr of the shell and the ideal position HI of intermediate stiffening ring. But these heights are considerably different between each other. To which of them our vertical stiffening elements should achieve? Considering the nonlinear behaviour of the steel, the effects of changes in geometry during loading and imperfections caused by welding works, the author tried to obtain an answer to this question.
{"title":"Necessary Height of the Vertical Stiffeners in Steel Silos on Discrete Supports with Accounting of Imperfections","authors":"Lyubomir A. Zdravkov","doi":"10.20898/j.iass.2020.002","DOIUrl":"https://doi.org/10.20898/j.iass.2020.002","url":null,"abstract":"To ensure unloading of the whole amount of stored product by gravity, the steel silos are often placed on supporting frame structure. The values of stresses in the joints between the thin shell and supporting frame elements are extremely high. It can cause local loss of stability in\u0000 the shell. To prevent it, many designers place stiffening elements above the supports. Here the question is how high should be the stiffening elements? The appropriate solution is that they should rise to that level till which the values of meridional normal stresses above the supports and\u0000 in the middle between them are equalized. But where is this level? Many researchers worked on values and ways of distribution of normal meridional stresses above the supports of the cylindrical shells. As a result of their efforts are determined critical height Hcr of the\u0000 shell and the ideal position HI of intermediate stiffening ring. But these heights are considerably different between each other. To which of them our vertical stiffening elements should achieve? Considering the nonlinear behaviour of the steel, the effects of changes in\u0000 geometry during loading and imperfections caused by welding works, the author tried to obtain an answer to this question.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90971573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.20898/j.iass.2020.005
S. Kato, Yutaka Niho
The load factor is one of the keys in anti-buckling design for safety together for construction cost, and studies have been becoming demanded in a recent situation that super large and super light spatial structures have been constructed. This paper investigates the relationship between reliability index β and snow load factor γs for anti-buckling design of a simply supported cylindrical lattice shell roof under simultaneous action of both dead load and asymmetric snow load. The cylindrical lattice shell analyzed is composed of an equilateral triangle grid of which members are of steel circular hollow sections. Members are connected rigidly to nodes at their both ends. The snow distribution as a main target is assumed in a way that the snow depth on the half of the arch-like roof is half of the amount on the other half roof. The snow fall depth is here assumed 50cm evaluated as 100-year return period, and its probability is assumed as Gumbel distribution with 100-year reference period. The probability distribution of buckling strength Pcr including geometrical and material nonlinearities is approximately evaluated based on a first-order perturbation. The reliability is calculated based on AFOSM, and the relationship in a form of β to γs is finally expressed for design use.
{"title":"Evaluation of Load Factor to Be Applied in Buckling Design of Cylindrical Lattice Shells Under Asymmetric Snow Load","authors":"S. Kato, Yutaka Niho","doi":"10.20898/j.iass.2020.005","DOIUrl":"https://doi.org/10.20898/j.iass.2020.005","url":null,"abstract":"The load factor is one of the keys in anti-buckling design for safety together for construction cost, and studies have been becoming demanded in a recent situation that super large and super light spatial structures have been constructed. This paper investigates the relationship between\u0000 reliability index β and snow load factor γs for anti-buckling design of a simply supported cylindrical lattice shell roof under simultaneous action of both dead load and asymmetric snow load. The cylindrical lattice shell analyzed is composed of an equilateral triangle\u0000 grid of which members are of steel circular hollow sections. Members are connected rigidly to nodes at their both ends. The snow distribution as a main target is assumed in a way that the snow depth on the half of the arch-like roof is half of the amount on the other half roof. The snow fall\u0000 depth is here assumed 50cm evaluated as 100-year return period, and its probability is assumed as Gumbel distribution with 100-year reference period. The probability distribution of buckling strength Pcr including geometrical and material nonlinearities is approximately evaluated\u0000 based on a first-order perturbation. The reliability is calculated based on AFOSM, and the relationship in a form of β to γs is finally expressed for design use.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82271626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.20898/j.iass.2020.004
G. Barazzetta, E. Mossa, C. Poggi, M. Simoncelli
The paper presents a complete study of the work done by Pier Luigi Nervi for the design and construction of a series of concrete hangars between 1935 and 1940. This research is enclosed in the framework of the exhibition entitled "Pier Luigi Nervi, il modello come strumento di progetto e costruzione" that gathers researches from Università degli Studi di Bologna, Università di Roma Tor Vergata and Politecnico di Milano. The exhibition was used as a starting point for a general discussion about the meaning of the logical passage that leads engineers and architects from physical scaled models to numerical structural models. The Politecnico di Milano contributed to re-writing the first experiences of Pier Luigi Nervi and Arturo Danusso in the structural modeling. Scaled models, nowadays substituted by finite element methods, were widely used in the past, for the understanding of the structural behavior of complex structures. Unfortunately, many of these masterpieces have been destroyed during the years (as happened to the two original models tested by Pier Luigi Nervi and reproduced for the exhibition). In the last part of the paper, based on numerical results, the structural behavior of these hangars is deeply discussed, underlining all the principal strengths and weaknesses of these complex structures.
本文对Pier Luigi Nervi在1935年至1940年间为设计和建造一系列混凝土机库所做的工作进行了全面研究。这项研究是在名为“Pier Luigi Nervi, il modello come strumento di progetto e costruzione”的展览框架内进行的，该展览汇集了博洛尼亚大学、罗马大学和米兰理工大学的研究成果。该展览被用作一般性讨论的起点，讨论将工程师和建筑师从物理比例模型引导到数值结构模型的逻辑通道的意义。米兰理工大学重新编写了Pier Luigi Nervi和Arturo Danusso在结构建模方面的第一次经验。比例模型在过去被广泛应用于复杂结构的结构行为的理解，现在被有限元方法所取代。不幸的是，这些杰作中的许多都在这些年里被摧毁了(就像Pier Luigi Nervi测试并为展览复制的两个原始模型一样)。在论文的最后一部分，根据数值结果，深入讨论了这些机库的结构性能，强调了这些复杂结构的所有主要优点和缺点。
{"title":"The Airplane Hangars of Pier Luigi Nervi: Digital and Scaled Models","authors":"G. Barazzetta, E. Mossa, C. Poggi, M. Simoncelli","doi":"10.20898/j.iass.2020.004","DOIUrl":"https://doi.org/10.20898/j.iass.2020.004","url":null,"abstract":"The paper presents a complete study of the work done by Pier Luigi Nervi for the design and construction of a series of concrete hangars between 1935 and 1940. This research is enclosed in the framework of the exhibition entitled \"Pier Luigi Nervi, il modello come strumento di\u0000 progetto e costruzione\" that gathers researches from Università degli Studi di Bologna, Università di Roma Tor Vergata and Politecnico di Milano. The exhibition was used as a starting point for a general discussion about the meaning of the logical passage that leads engineers\u0000 and architects from physical scaled models to numerical structural models. The Politecnico di Milano contributed to re-writing the first experiences of Pier Luigi Nervi and Arturo Danusso in the structural modeling. Scaled models, nowadays substituted by finite element methods, were widely\u0000 used in the past, for the understanding of the structural behavior of complex structures. Unfortunately, many of these masterpieces have been destroyed during the years (as happened to the two original models tested by Pier Luigi Nervi and reproduced for the exhibition). In the\u0000 last part of the paper, based on numerical results, the structural behavior of these hangars is deeply discussed, underlining all the principal strengths and weaknesses of these complex structures.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91218544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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