{"title":"Non-Parametric Shape Design of Free-Form Shells Using Fairness Measures and Discrete Differential Geometry","authors":"M. Ohsaki, K. Hayakawa","doi":"10.20898/j.iass.2021.007","DOIUrl":"https://doi.org/10.20898/j.iass.2021.007","url":null,"abstract":"A non-parametric approach is proposed for shape design of free-form shells discretized into triangular mesh. The discretized forms of curvatures are used for computing the fairness measures of the surface. The measures are defined as the area of the offset surface and the generalized\u0000 form of the Gauss map. Gaussian curvature and mean curvature are computed using the angle defect and the cotangent formula, respectively, defined in the field of discrete differential geometry. Optimization problems are formulated for minimizing various fairness measures for shells with specified\u0000 boundary conditions. A piecewise developable surface can be obtained without a priori assignment of the internal boundary. Effectiveness of the proposed method for generating various surface shapes is demonstrated in the numerical examples.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45929179","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}
{"title":"Structural Morphogenesis for RC Free-Form Surface Shell with Arbitrary Boundary Shape And Opening - Comparison of Optimal Solution and Application of Decent Solutions Search Method","authors":"Kodai Nagata, T. Honma","doi":"10.20898/j.iass.2021.014","DOIUrl":"https://doi.org/10.20898/j.iass.2021.014","url":null,"abstract":"In this paper, artificial bee colony (ABC) to obtain the decent solutions that the authors proposed is applied to the structural morphogenesis for RC (Reinforced-Concrete) free-form surface shell with arbitrary boundary shape. The 'decent solutions' have relatively high evaluation solutions\u0000 that maintain the diversity of the design variable space, including the global optimal solution and local optimal solutions. In this paper, we focus on an opening of RC free form surface shell structures considering design and functionality, and the structural morphogenesis procedure that\u0000 considers constraints of the excessive bending moment caused by the presence of an opening in the shell is proposed. Numerical results demonstrate the efficacy of a structural morphogenesis procedure that simultaneously considers shell shape, thickness, and opening as design variables. Furthermore,\u0000 it is shown that proposed structural morphogenesis using decent solutions search method can support a designer's idea of architectural forms having a relationship between shape and mechanical behavior at the initial stage of design.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43531944","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}
{"title":"Illustrating Membrane-Dominated Regimes in Pressurized Thin Shells","authors":"A. Niewiarowski, S. Adriaenssens, R. M. Pauletti","doi":"10.20898/j.iass.2021.017","DOIUrl":"https://doi.org/10.20898/j.iass.2021.017","url":null,"abstract":"Pressurized thin-wall structures cover a broad range of applications, including storage tanks, pressurized rubber flood barriers, and large span enclosures. To accurately model such structures, the analyst must select the appropriate mechanical formulation (e.g.membrane vs shell). Membranes\u0000 are assumed to have negligible bending stiffness and respond to compression by wrinkling; shells resist axial compression (before buckling) and bending efficiently. While theoretical research on these differences is vast, this study aims to explicitly clarify the consequences of this choice\u0000 and permit a comparison of error between membrane and shell formulations. Therefore, this paper presents a parametric study of canonical pressurized thin-wall structural geometries (i.e.semi-cylinder, hemisphere) to illustrate the transitions between membrane and bending dominant behavior.\u0000 The mathematical models of a pneumatic 5-parameter shell and membrane are presented and employed to quantify the effects of variables such as thickness and geometry on the amount of membrane, bending, and shear energy. The effects of inflation pressure, self-weight, and hydrostatic loads are\u0000 also considered. The graphical results, presented in terms of dimensionless quantities in the design space, are general and should be of interest to the theorist and practitioner alike.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42253275","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}
{"title":"Numerical Impact Analysis of Folding-Induced Tubular Thin-walled Energy-dissipating Elements","authors":"E. Ruocco, Antonia Giovenale, Danilo Di Giacinto","doi":"10.20898/j.iass.2021.013","DOIUrl":"https://doi.org/10.20898/j.iass.2021.013","url":null,"abstract":"This paper deals with the numerical impact analysis of tubular thin-walled steel-made elements with induced folding for energy dissipation application. The excellent deceleration of the impacting mass of axial collapsing structures favors their use in energy dissipation applications,\u0000 such as impact resistance and rockfall protection. Dynamic Finite Element analyses have been carried out to evaluate the performance of vertical assemblies of cold-formed steel cell-shaped elements welded on each other to form collapsible tubular elements. In turn, these have been gathered\u0000 in groups and restrained by galvanized steel wires to create modules. The axial collapse, which is the most effective energy absorption mechanism, has been triggered by shaping the elements' edge as serpentine. In the analysis, several assembly configurations have been subjected to a freefall\u0000 rhombicuboctahedron-shaped rigid block impact; Falling height, impact angle, and block mass have been varied to investigate their effect on the performance. The numerical results show a good agreement when compared to those obtained through a real-scale experiment.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44864432","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}
{"title":"Evolutionary Topology Optimization of Spatial Steel-Concrete Structures","authors":"Yu Li, Y. Xie","doi":"10.20898/j.iass.2021.015","DOIUrl":"https://doi.org/10.20898/j.iass.2021.015","url":null,"abstract":"Topology optimization techniques based on finite element analysis have been widely used in many fields, but most of the research and applications are based on single-material structures. Extended from the bi-directional evolutionary structural optimization (BESO) method, a new topology\u0000 optimization technique for 3D structures made of multiple materials is presented in this paper. According to the sum of each element's principal stresses in the design domain, a material more suitable for this element would be assigned. Numerical examples of a steel- concrete cantilever, two\u0000 different bridges and four floor systems are provided to demonstrate the effectiveness and practical value of the proposed method for the conceptual design of composite structures made of steel and concrete.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46702761","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}
{"title":"Parametric Analysis of the Dome of the Sports Palace of Mexico City","authors":"E. González, G. Marco, C. Gonzalez, J. Galindo","doi":"10.20898/J.IASS.2021.004","DOIUrl":"https://doi.org/10.20898/J.IASS.2021.004","url":null,"abstract":"The Sports Palace of Mexico City was built in 1968 and became a turning point in the design and construction of laminar shells, leading the transition from reinforced concrete to metallic grid structures. Felix Candela observed that the use of concrete in designing laminar structures\u0000 was limited to achieve great spans for sport spaces; he thus changed his first proposal for using a concrete laminar shell to a metallic structure. However, in the first architectural conception of the metallic structure, a lighter cable structure was proposed respecting the built geometry,\u0000 with the intent of using high-strength wires in the upper and lower chords of the arches. In this paper, three different proposals are modeled. The first uses a 3D modelled concrete shell for understanding the geometry. The others use the final geometry and are analyzed using advanced NURBS\u0000 (Non-uniform rational Bspline) modeling techniques with Rhinoceros and a parametric design with Grasshopper, where the parameters and results obtained in previous tests are compared with the results obtained in the simulations. Paneling plugins, forces simulation add-ons, finite elements analysis\u0000 and environmental design simulation tools in Grasshopper are used to compare the results under normal design conditions.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":"140 1","pages":"50-60"},"PeriodicalIF":0.8,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75848566","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}
{"title":"Buckling Load Estimation of Two-way Grid Domes Stiffened by Diagonal Braces Under Vertical Load","authors":"S. Kato, S. Nakazawa, Y. Mukaiyama, T. Iwamoto","doi":"10.20898/J.IASS.2021.001","DOIUrl":"https://doi.org/10.20898/J.IASS.2021.001","url":null,"abstract":"The present study proposes an efficient scheme to estimate elastic-plastic buckling load of a shallow grid dome stiffened by diagonal braces. The dome is circular in plan. It is assumed to be subject to a uniform vertical load and to be supported by a substructure composed of columns\u0000 and anti-earthquake braces. Based on FEM parametric studies considering various configurations and degrees of local imperfections, a set of formulations are presented to estimate the elastic-plastic buckling load. In the scheme, the linear buckling load, elastic buckling load, and imperfection\u0000 sensitivity are first presented in terms of related parameters, and the elasticplastic buckling load is then estimated by a semi-empirical formula in terms of generalized slenderness ratio using a corresponding plastic load. For the plastic load, the present scheme adopts a procedure that\u0000 it is calculated by a linear elastic FEM analysis, while an alternative formula for the plastic load is also proposed based on a shell membrane theory. The validity of the estimation scheme is finally confirmed through comparison with the results based on FEM nonlinear analysis. The formulations\u0000 are so efficient and simple that the estimation may be conducted for preliminary design purposes almost with a calculator. .","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":"42 1","pages":"7-23"},"PeriodicalIF":0.8,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73121361","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}
{"title":"Calculation and Analysis of Hydraulic Automatic Climbing Formwork Equipment for Super-high Building Construction","authors":"Juwei Xia, Yun-long Yao, Xiao-shun Wu, Yuan-hong Chen","doi":"10.20898/J.IASS.2021.003","DOIUrl":"https://doi.org/10.20898/J.IASS.2021.003","url":null,"abstract":"Hydraulic automatic climbing formwork equipment is widely used in super-high-rise building construction due to its advantages of simple operation, fast construction speed, low cost, and high automation. Quantitative calculation of the mechanical state of climbing formwork equipment\u0000 is an important technical means of ensuring safety during super-high building construction. This work thus introduces a hydraulic climbing formwork equipment structure and subsequently analyzes the construction process and the main working state of the hydraulic climbing formwork equipment.\u0000 Then, for the design of the outer climbing frame of the hydraulic climbing formwork, an approximate analytical method for solving the node reaction force is proposed. Finally, combined with the actual engineering, the calculation results of the approximate analytical method and the finite\u0000 element method are compared, and the calculation and analysis methods of the hydraulic climbing formwork equipment frame and key nodes are introduced. The calculation analysis process and related conclusions can be used as engineering reference for similar projects.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":"2012 1","pages":"24-36"},"PeriodicalIF":0.8,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89519355","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}
{"title":"Global Stability Behaviour of Single-Layer Reticulated Domes Created Using a New Nomenclature","authors":"Ranjith Kolakkattil, Arul S Jayachandran","doi":"10.20898/j.iass.2021.012","DOIUrl":"https://doi.org/10.20898/j.iass.2021.012","url":null,"abstract":"The primary objective of the paper is to investigate the post buckled behaviour of the single-layered Kite geometry dome developed using a novel crystallographic parameterisation principle. Both triangulated and non-triangulated domes are evolved based on the crystallographic parameterisation principles. It brings in a unique nomenclature for identifying different tessellations in reticulated single-layer dome configurations. This nomenclature brings in a physical meaning to dome tessellations instead of being called by the inventors such as Schwedler dome etc. In this paper, the effect of surface pattern on the load capacity of dome configuration is demonstrated with the comparison of domes having different surface patterns. The comparison of post-buckling behaviour of two different single-layer dome configurations - Kiewitt dome and Kite dome is presented. Despite having rigid nodal joints, the load capacity of the dome is significantly reduced when subjected to unsymmetrical and collateral loads due to the localised effect of these loads and the increased chance of snap-through compared to symmetrical uniform loading acting all over the structure. The Kite geometry have higher performance under uniform gravity loading with a low rise to span ratio.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67610111","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}
{"title":"Form Finding and Analysis of an Active Bending- Pantographic Bamboo Space Structure","authors":"M. Seixas, L. E. Moreira, P. Stoffel, J. Bina","doi":"10.20898/J.IASS.2021.005","DOIUrl":"https://doi.org/10.20898/J.IASS.2021.005","url":null,"abstract":"This paper presents the form finding and structural analysis of an active bending-pantographic bamboo space structure that integrates self-stressed active bending arches, tensile pantographic grids and supporting bipods. The structure was designed to roof an open-aired amphitheater in the tropical climate. The structure has a self-supporting behavior and a mobile assembly procedure, applying the hinged flexible connection (HFC) mechanism. The structure was developed initially through small-scale physical models, then, on computer models and full-scale prototypes. Empirical models were used to determine the minimum bending radius of the arches and served to embed data for the computer models. The active bending arch (ABA) applied Phyllostachys aurea bamboo rods subjected to axial loads up to the elastic limit of strain on the beams. Steel cables and diagonal rods were connected to the curved beams, avoiding buckling in the plane of the arches. Modular pantographic grids were deployed over the ABA, generating double curved space frames with free-form geometries. The coupling of active bending arches and pantographic grids resulted in a hybrid structure, with mutual operation of bending-active and form-active structural modules. The developed structure used bio-based materials for a sustainable engineering design, with lightweight techniques and low-carbon footprint.","PeriodicalId":42855,"journal":{"name":"Journal of the International Association for Shell and Spatial Structures","volume":"56 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84538222","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}