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Journal articles on the topic 'Shell of the building'
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1
Chang, Jing Yi, and Yean Der Kuan. "Application of CFD to Building Thermal Control Analysis." Applied Mechanics and Materials 271-272 (December 2012): 777–81. http://dx.doi.org/10.4028/www.scientific.net/amm.271-272.777.
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Building-integrated photovoltaic system is to import a photovoltaic panel system into the shell structure of a building by using building design techniques, so that the system constituents not only generate power, but are also a part of the building’s shell. If the photovoltaic panel is integrated with a sun shield, a power benefit could be obtained and both solar irradiation and the cooling load could be reduced. This study aimed to use CFD technology for analysis of building surface thermal control and flow field simulation, and further discuss the effects of the relative position of the sun and atmospheric wind flow field on the distribution of building surface temperatures and flow fields at different hours and in different seasons. Understanding the sun's position and other climatic conditions accurately is helpful for locating solar panels and solar collectors on buildings.
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Qahorov, K. Q., O. E. Sysoev, and E. O. Sysoev. "Influence of Class of Concrete on Oscillations of Thin-Wall Cylindrical Reinforced Concrete Shells." Materials Science Forum 992 (May 2020): 59–65. http://dx.doi.org/10.4028/www.scientific.net/msf.992.59.
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Thin-walled cylindrical shell made of reinforced concrete, is widely used in the construction of buildings and structures as coatings and forms of architecture of buildings. Thin-walled shell its shape can give entertainment to the architectural design of buildings, and their rigidity helps to block large spans, creating more closure of the room without additional supports. Another advantage of using cloud forms of structures is the efficiency of this design, since for the manufacture of shell forms of structures less construction material is spent than any other design for coating. The purpose of theoretical calculations and the studied excrement over reinforced concrete shells with different elastic modules, is to ensure reliability in the operation of buildings and structures, and to exclude accidents arising resonance phenomena of free vibrations of the shells from the effects of external forces (loads). On the basis of the laboratories of Komsomolsk-on-Amur state University in the laboratory of building materials and structures, experimental studies were conducted to determine the spectra of forced and free vibrations of the reinforced concrete shell with different elastic modules. The purpose of research on reinforced concrete shells is to determine the oscillation frequencies at different locations of the combined masses. The article deals with the theoretical calculation based on the equation of the theory of flat thin-walled shells, using the Bubnov-Galerkin method, by which we determine how the parameters of the shell affect the process of free oscillation.
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Dutt, A. J. "Wind Pressure Distribution on a Multiple Hyperbolic Paraboloid Shell Roof Building." International Journal of Space Structures 2, no. 1 (March 1987): 49–54. http://dx.doi.org/10.1177/026635118700200105.
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Wind pressure distribution was investigated on a multiple hyperbolic paraboloid (HP) shell roof building by model test in the wind tunnel. The roof of the model was a grouping of four similar HP shells in a ‘normal’ array forming a square in plan. Wind tunnel experiments were carried out; wind pressure distribution and the contours of wind pressure on shell roof and walls were determined for various wind directions. The average suctions on roof were computed and compared with those on a single HP shell roof and on a multiple HP shell roof having a ‘sawtooth’ array. The highest point suction encountered was −4·12 q whilst the maximum average suction on the roof was −0·61 q.
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Byrdina, Marina V., Mikhail F. Mitsik, Lema A. Bekmurzaev, Svetlana V. Kurenova, and Anastasiya A. Movchun. "Building of a space form of the flexible inextensible one-layer conic shell." Nexo Revista Científica 34, no. 01 (April 15, 2021): 489–503. http://dx.doi.org/10.5377/nexo.v34i01.11326.
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The paper covers the visualization of a volume-space form of the flexible inextensible one-layer shell that is represented in the stress and strain state appearing during fastening the shell on the upper edge and its free location below the fastening border in the field of gravitational and elastic forces of the material. With no account taken of the gravitational forces, the shell is a right circular flattened cone. A developed program module can be used in designing and calculating the thin-wall shell structures during their non-linear deformation and their visualization. Visualization of the space form of the shell structure can be used for simulating various products, for instance, the cone antennae or the textile products, flexible elastic shells in the hydraulic engineering, etc.
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Krivoshapko, Sergey N. "Optimal shells of revolution and main optimizations." Structural Mechanics of Engineering Constructions and Buildings 15, no. 3 (December 15, 2019): 201–9. http://dx.doi.org/10.22363/1815-5235-2019-15-3-201-209.
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Introduction. Optimization is a criterion, on the ground of which, comparative estimation of possible alternatives and selection of the best decisions is carried out. Cost of a shell, its minimum weight, absence of bending moments and tensile normal stresses, given stress state for acting external load, given bearing capacity when optimal shallowness, maximum external load, minimum weight under limitation on the value of natural frequencies of vibration and maximum displacements, absence of bending moments with taking into account internal pressure, dead weight, and centrifugal forces; maximum of critical force and something else can be criterion of selection of optimal shape of shell of revolution. Methods. The main criteria of optimality for shells of revolution and information sources for the 1970-2019 periods are presented in a paper. It will help to study previous results devoted to using optimizations and to set about further investigation. But there is no single approach to the definition of optimal shell of revolution and obviously will not be, because own optimizations are necessary for every concrete case of loading, or distribution of stresses along the thickness, or under the demands to the ratio of the volume and area of considered shell, or with due regard for different kind of expenses, and other demands. Results. For the first time, 24 criteria of optimality only for shells of revolution were discovered. The names of scientists offered presented criteria of optimality and the 45 references dealing with this question are pointed out. It is shown that principles put in the basis of optimal design and criteria of optimality must be given with the help of language quite naturally for computer. Having used optimi- For citation Krivoshapko S.N. (2019). Optimal shells of revolution and main optimizations. Structural Mechanics of Engineering Constructions and Buildings, 15 (3), 201-209. http://dx.doi.org/ 10.22363/1815-5235-2019-15-3-201-209 zations presented in the paper, designers can choose the criterion for their own design of optimal shell shape. Study of the prerequisites of the structural solutions in building and machine-building, the history of the development and perfecting of technologies of erection of shells of revolution will permit to generalize the experience accumulated by designers and to develop new fundamental solutions. Otherwise, architects, structural engineers, and designers will be repeating the achieved solutions in building, architecture, and machine-building.
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Huterer, J., E. C. Ha, D. G. Brown, and P. C. Cheng. "Darlington GS vacuum building - Containment shell." Nuclear Engineering and Design 85, no. 2 (March 1985): 131–40. http://dx.doi.org/10.1016/0029-5493(85)90279-1.
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Mehrabian, Sahereh, Golzar Younesi, and Farzan Rasoulzadeh. "Creation Sustainable Building Shell Using Smart Materials." Advanced Materials Research 685 (April 2013): 240–44. http://dx.doi.org/10.4028/www.scientific.net/amr.685.240.
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It’s been almost a decade that the idea of smart materials has attracted man’s attention. These materials are capable of responding to their surrounding environment and of adapting to it. The development pace of construction materials has also been towards multi-purpose and smart materials, which would ultimately result in manufacturing phase matters. In fact, the existence of smart structural materials and systems has played a substantial role in developing the idea of the smart control of a construction. These materials can improve designing methods and the construction of buildings. In the sustainable buildings design approach (a new approach to designing buildings which should meet a high level of environmental standards with an emphasis on the costs of their useful lifespan), such highly efficient materials are used because they are more adaptable to the environment and increase a building’s useful lifespan. In this article, some of the smart materials used for the façade are introduced and their performances will be studied. It is concluded that using such technologies requires less energy and very little amounts of chemicals and detergents which could be a step taken towards achieving sustainable architectural and environmental goals.
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Idoum, Aicha, Lahcen Bammou, Rachid Tiskatine, and Ahmed Aharoune. "Thermal conductivity of clay based material incorporating Argan Shell: Experimental characterization." E3S Web of Conferences 229 (2021): 01032. http://dx.doi.org/10.1051/e3sconf/202122901032.
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This research investigated the impact of agricultural biomass additives (Argan shell) on the thermal and physical properties of fired clay bricks for building application. The objective of the study is to characterize the selected materials from molecule up to the final materials used in buildings. The materials used in this study, are soil and Argan shells, locally available materials for brick making. The Argan shells were grinded and then added to the clay mixture. The Clay brick shows a formation of pores during the firing process up to 1050°C. As results, the bulk density of the clay bricks decreased due to the pores formation. On the other hand, the thermal conductivity of the clay bricks was reduced by 53% using 20wt% of the biomass additives.
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Pronozin, Yakov, Tatyana Maltseva, Oleg Poroshin, and Anna Medvedeva. "Thin-walled shell foundations." MATEC Web of Conferences 265 (2019): 05032. http://dx.doi.org/10.1051/matecconf/201926505032.
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The article presents a study of the interaction of strip foundations of multistorey apartment houses united by flat cylindrical shells with a ground base. The foundation of a 17-storey residential building has been taken as an example. The ground base consists of strong upper and highly compressible underlying layers. The use of traditional foundations under the specified conditions is hardly possible. The calculation scheme of the building and the stages of the ground foundation work are represented. Also, the researchers share the results of geotechnical monitoring in the construction process including observations of settlings at 25 points with an accuracy of 0.1 mm and measurement of layer-by-layer deformations of the ground base under the building to a depth of 10 meters from the surface. The diagrams demonstrate the actual settlement of the building with increasing load and layer-by-layer deformations of the ground base in depth are presented.
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Krivoshapko, Sergey N., and Vyacheslav N. Ivanov. "Simplified selection of optimal shell of revolution." Structural Mechanics of Engineering Constructions and Buildings 15, no. 6 (December 15, 2019): 438–48. http://dx.doi.org/10.22363/1815-5235-2019-15-6-438-448.
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Relevance. Architects and engineers, designing shells of revolution, use in their projects, as a rule, spherical shells, paraboloids, hyperboloids, and ellipsoids of revolution well proved themselves. But near hundreds of other surfaces of revolution, which can be applied with success in building and in machine-building, are known. Methods. Optimization problem of design of axisymmetric shell subjected to given external load is under consideration. As usual, the solution of this problem consists in the finding of shape of the meridian and in the distribution of the shell thickness along the meridian. In the paper, the narrower problem is considered. That is a selection of the shell shape from several known types, the middle surfaces of which can be given by parametrical equations. The results of static strength analyses of the domes of different Gaussian curvature with the same overall dimensions subjected to the uniformly distributed surface load are presented. Variational-difference energy method of analysis is used. Results. Comparison of results of strength analyses of six selected domes showed that a paraboloid of revolution and a dome with a middle surface in the form of the surface of rotation of the z = - a cosh( x/b ) curve around the Oz axis have the better indices of stress-strain state. These domes work almost in the momentless state and it is very well for thin-walled shell structures. New criterion of optimality can be called “minimum normal stresses in shells of revolution with the same overall dimensions, boundary conditions, and external load”.
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Calladine, Christopher R. "Shell buckling, without ‘imperfections’." Advances in Structural Engineering 21, no. 16 (February 27, 2018): 2393–403. http://dx.doi.org/10.1177/1369433217751585.
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The buckling behaviour of thin shell structures under load has been a persistent challenge to engineering designers and researchers over many decades. In this article I consider two unusual experimental studies on the buckling of thin-walled elastic cylindrical shells, each of which sheds intriguing light on the buckling phenomena. The classical theory of buckling of thin cylindrical shells under axial compression predicts that the buckling stress will be proportional to t/ R– the ratio of thickness to radius – other things being equal. But collected results of experimental studies from many laboratories, when plotted on log–log scales, show clearly that the buckling stress is actually proportional to ( t/ R)1.5, with the measured buckling stresses being scattered through a factor of about 4 for shells with R/ t > 200. Such scatter is commonly judged to be in accord with Koiter’s theory of ‘imperfection sensitivity’. But that theory lays no claim to an understanding of the empirical 1.5-power law. I claim that a key to this situation is the experimental performance of some small-scale open-topped silicone rubber shells, buckling under their own weight, which clearly demonstrates a 1.5-power law, but with very little scatter. The buckling mode of these shells involves almost entirely inextensional deformation, with a single small dimple growing near the base, separated from the rest of the shell by a narrow boundary layer that accounts for almost all of the dimple’s elastic strain energy. A straightforward, simple analysis of the mechanics of the dimple is consistent with the experimental 1.5-power law. As noted above, experimental buckling loads of shells that are closed at both ends also show the empirical 1.5-power law, but now with significant statistical scatter. A second aim of the paper is to throw light on that phenomenon. I venture to attribute it to the effect of the boundary conditions of the shell. I adduce support for this view from experimental observations on the buckling of a shell with special, frictional end-fittings. That feature produces significantly higher collapse loads, and with much smaller scatter, than for corresponding shells with fixed boundaries; and it permits striking pre-buckled deformations to occur, of a kind not previously noted. It will be appreciated that neither of the two parts of this article depends on the widely accepted theory of imperfection-sensitivity; hence my choice of title. It is a pleasure for me to submit this article to a special publication in honour of Michael Rotter, with whom I have discussed matters of this sort through three decades.
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Prokopska, Aleksandra, and Jacek Abramczyk. "Responsive Parametric Building Free Forms Determined by Their Elastically Transformed Steel Shell Roofs." Buildings 9, no. 2 (February 14, 2019): 46. http://dx.doi.org/10.3390/buildings9020046.
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The article concerns the unconventional architectural forms of buildings roofed with transformed shells made up of thin-walled steel fold sheets, and a parametric description of how they are shaped. Complicated deformations of flanges and webs, as well as the complex static–strength work of the folds in a shell roof, demand the creation of simplified models regarding the parameterization of such shells and their integration with the general forms of the buildings. To obtain favorable results, it was necessary to write computer applications because of both the complicated problems related to the significant limitations of the transformations, as well as the great possibilities of shaping shell roofs by means of directrices of almost free shape and mutual position. The developed procedures enable the prediction of shapes and states of all the folds in the designed shell. They take account of two basic conditions related to these restrictions, which guarantee that the folds encounter little resistance when matching their transformed forms to the roof directrices, and that their initial effort was as low as possible. The developed procedures required solving a number of issues in the fields of architecture, civil engineering, and structures, and are illustrated with an example of shaping one unconventional architectural form. The interdisciplinary study explains a new insight into shaping such forms.
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Abramczyk, Jacek. "Transformed Corrugated Shell Units Used as a Material Determining Unconventional Forms of Complex Building Structures." Materials 14, no. 9 (May 5, 2021): 2402. http://dx.doi.org/10.3390/ma14092402.
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This article is an insight into interdisciplinary topics in the field of civil engineering, morphology, architecture, mechanics, and computer programming. A novel method for shaping unconventional complex roofs in which regular folded units transformed into various shells are used as a complex substitute material is proposed. The original method’s algorithm for building systems of planes defining diversified polyhedral networks in the three-dimensional space by means of division coefficients of the subsequently determined vertices is presented. The algorithm is based on the proportions between the lengths of the edges of the reference network, the location and shape of the ruled shell units included in the designed complex roof structure, so it is intuitive. The shell units are made up of nominally flat folded sheets transformed effectively into shell forms whose static-strength properties are controlled by geometric quantities characteristic of ruled surfaces. The presented original approach to the shaping of the shell roof structures determining specific complex building forms allows us to go beyond the limitations related to the orthotropic structure of the folded roof sheeting and the shape transformations.
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Wales, David J. "Closed-shell structures and the building game." Chemical Physics Letters 141, no. 6 (November 1987): 478–84. http://dx.doi.org/10.1016/0009-2614(87)85064-9.
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Yazici, Sevil. "Building in Extraterrestrial Environments: T-Brick Shell." Journal of Architectural Engineering 24, no. 1 (March 2018): 04017037. http://dx.doi.org/10.1061/(asce)ae.1943-5568.0000293.
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Wang, Xi, Ruo-qiang Feng, Gui-rong Yan, Bao-chen Zhu, and Feng-cheng Liu. "Buckling mechanism of cable-stiffened lattice shells with bolted connections." Advances in Structural Engineering 22, no. 15 (July 7, 2019): 3234–48. http://dx.doi.org/10.1177/1369433219862098.
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The cable-stiffened lattice shell is a new structural system for its translucence and lighting. This article discusses the effect of the connections’ behavior and geometric imperfection on the structural stability and reveals the buckling mechanism of the cable-stiffened lattice shell. The spring stiffness for bolted connections of cable-stiffened lattice shells is deduced from the spring in series model. The buckling mechanism of cable-stiffened lattice shells with three types of joints have been studied based on the prototypical static experiments of bolted connections. The decrease of bolted connections’ stiffness would lead to the change in the displacement distribution for the lattice shell under its ultimate load. The buckling loads and initial structural stiffness of cable-stiffened lattice shells with shim-strengthened bolted joints are approximately 80% of those for cable-stiffened lattice shells with rigid joints. The result indicates that the buckling loads of cable-stiffened lattice shells with bolted connections decrease much more slowly than the decrease of bolted connections’ stiffness. The cable-stiffened lattice shell with SBP connections is more sensitive to the initial geometric imperfection. Finally, a formula has been proposed for estimating buckling loads of elliptic paraboloid cable-stiffened lattice shells with bolted connections.
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Llamosa, D., M. Ruano, L. Martínez, A. Mayoral, E. Roman, M. García-Hernández, and Y. Huttel. "The ultimate step towards a tailored engineering of core@shell and core@shell@shell nanoparticles." Nanoscale 6, no. 22 (2014): 13483–86. http://dx.doi.org/10.1039/c4nr02913e.
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Core@shell and core@shell@shell nanoparticles are building blocks for more sophisticated systems and a plethora of applications. The one-step generation of such complex nanoparticles is reported where the atoms of the core and shell can be easily inverted, avoiding intrinsic constraints of chemical methods.
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Andriichuk, О. V., and S. O. Uzhehov. "THE FRACTURE TOUGHNESS OF THIN-WALLED COVER SHELLS HYPERBOLIC PARABOLOID SHAPED OF FERROCEMENT AND STEEL FIBER CONCRETE UNDER THE ACTION OF OPERATING LOADS." Ресурсоекономні матеріали, конструкції, будівлі та споруди, no. 37 (January 30, 2020): 89–96. http://dx.doi.org/10.31713/budres.v0i37.334.
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Experimental research of new materials and structures with improved parameters of strength, fracture toughness, bearing capacity and their lifetime in comparison with typical elements is an actual problem of building science.Nowadays there is a trend to design and use for buildings covering the new design solutions as the thin shells. One of the types of thin shells are Gaussian shells with negative curvature. It’s worth to note that in the last decade, a considerable number of researches of thin-walled structures made of steel fiber reinforced concrete were conducted, which confirmed the efficiency of its use to enhance their hardness, fracture toughness and thus longer life.The article presents the results of the authors’ experimental studies of fracture toughness of thin-walled cover structures with Gaussian negative curvature in the shape of hyperbolic paraboloid made of ferrocement and steel fiber reinforced concrete under the action of the operating load.The load application was carried out for ten steps, after each step the pause was for 15...20 min, during which the data of the strain-gauge station VNP-8 was recorded, using a microscope were measured and recorded the width of the cracks, deflections of the structure were measured etc.The external force was evenly-distributed to its applications and the impact was simulated according to the real conditions of construction use.The experimental part of the research was conducted at the laboratory of building materials and structures of Lutsk National Technical University. In scientific work carried out mapping and comparison of the obtained experimental results, carried out processing and analysis, presents the conclusions.During the researches it was found that the fracture toughness of thin-walled shell cover with Gaussian negative curvature in the shape of a hyperbolic paraboloid with dispersed reinforcement (steel fiber reinforced concrete) is higher than in the shell made of ferrocement. Accordingly, it can be argued about the increasing of the lifetime of steel fiber reinforced concrete shell covering in comparison with the ferrocement shell.
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AbouElhamd, Amira, Khaled Al-Sallal, and Ahmed Hassan. "Review of Core/Shell Quantum Dots Technology Integrated into Building’s Glazing." Energies 12, no. 6 (March 19, 2019): 1058. http://dx.doi.org/10.3390/en12061058.
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Skylights and windows are building openings that enhance human comfort and well-being in various ways. Recently, a massive drive is witnessed to replace traditional openings with building integrated photovoltaic (BIPV) systems to generate power in a bid to reduce buildings’ energy. The problem with most of the BIPV glazing lies in the obstruction of occupants’ vision of the outdoor view. In order to resolve this problem, new technology has emerged that utilizes quantum dots semiconductors (QDs) in glazing systems. QDs can absorb and re-emit the incoming radiation in the desired direction with the tunable spectrum, which renders them favorable for building integration. By redirecting the radiation towards edges of the glazing, they can be categorized as luminescent solar concentrators (QD-LSCs) that can help to generate electricity while maintaining transparency in the glazing. The aim of this paper is to review the different properties of core/shell quantum dots and their potential applications in buildings. Literature from various disciplines was reviewed to establish correlations between the optical and electrical properties of different types, sizes, thicknesses, and concentration ratios of QDs when used in transparent glazing. The current article will help building designers and system integrators assess the merits of integrating QDs on windows/skylights with regards to energy production and potential impact on admitted daylighting and visual comfort.
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Teng, J. G., H. T. Wong, Z. C. Wang, and S. L. Dong. "Steel-Concrete Composite Shell Roofs: Structural Concept and Feasibility." Advances in Structural Engineering 8, no. 3 (July 2005): 287–307. http://dx.doi.org/10.1260/1369433054349105.
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This paper describes a new structural system, namely steel-concrete composite shells, for enclosing large spaces and presents test and numerical simulation results to demonstrate its feasibility. These composite shells are formed by pouring concrete on a thin stiffened steel base shell which serves as both the permanent formwork and the tensile steel reinforcement. The thin steel shell, constructed by bolting together open-topped modular units consisting of a base plate with surrounding edge plates, is a steel shell with thin stiffeners in both directions. The new system retains all the benefits of thin concrete shells, but eliminates the need for temporary formwork and minimises the required falsework. In this paper, the background to the development of this new structural system is first given, followed by a description of its structural features. Advantages of this new structural system over existing systems are next discussed. Possible failure modes of the new structural system are also outlined. Finally, a study to demonstrate the feasibility of constructing these shell roofs of large spans with very thin steel sheets and a limited amount of shoring is presented. In this feasibility study, a finite element model was developed for bolted steel arches as a conservative approximation of bolted steel shells, and was verified using results from simple connection tests. Both the connection tests and the verification of the finite element model are given in this paper before presenting the results from the parametric study.
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Prabu, B., N. Bujjibabu, S. Saravanan, and A. Venkatraman. "Effect of a Dent of Different Sizes and Angles of Inclination on Buckling Strength of a Short Stainless Steel Cylindrical Shell Subjected to Uniform Axial Compression." Advances in Structural Engineering 10, no. 5 (October 2007): 581–91. http://dx.doi.org/10.1260/136943307782417735.
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Generally, thin cylindrical shells are susceptible for geometrical imperfections like non-circularity, non-cylindricity, dents, swellings etc. All these geometrical imperfections decrease the static buckling strength of thin cylindrical shells, but in this paper only effect of a dent on strength of a short (L / D ∼1 and R/t = 280) stainless steel cylindrical shell is considered for analysis. The dent is modeled on the FE surface of perfect cylindrical shell for different angles of inclination and sizes at half the height of cylindrical shell. The cylindrical shells with a dent are analyzed using non-linear static buckling analysis. From the results it is found that in case of shorter dents, size and angle of inclination dents do not have much effect on static buckling strength of thin cylindrical shells, where as in the case of long dents, size and angle of inclination of dents have significant effect. But both short and long dents reduce the static buckling strength drastically.
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Godycki-Ćwirko, T., K. Nagrodzka-Godycka, and P. Piotrkowski. "Dome Over The Gdynia Seaport Building." Archives of Civil Engineering 60, no. 2 (June 1, 2014): 223–40. http://dx.doi.org/10.2478/ace-2014-0015.
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Abstract The paper presents the description of structure and the selected problems of the technical condition, as well as the strength analysis of the thin-walled reinforced concrete shell which has been making a covering of the main hall of the Gdynia Seaport Building through the last 80 years. The rectangle projection of four single curvature shells of the dome was shaped out of mutual perpendicular intersection of two cylindrical shells. The analysis of the state of stress and deformations was carried out using the special model worked out in MES considering the combination of loads, the thermal ones included. For the long lasting loads (the deadweight of the dome), the computed results of static quantities were confronted with analytical results obtained according to F. Dischinger’s method. This method had been applied by the DYWIDAG Company in Berlin and its branch in Katowice (Poland) who designed the Gdynia Dome. The computational analysis and the assessment of the technical state, along with laboratory pH tests of concrete, made it possible to carry out the overall evaluation of durability and safety of operation of the Gdynia Seaport Dome through the next decades.
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Shingu, Kiyoshi, and Kiyotoshi Hiratsuka. "Dynamic Response of Base Isolated Rotational Shell with Edge Beam and Fuzzy Vibration Control of the Shell." International Journal of Space Structures 12, no. 3-4 (September 1997): 173–79. http://dx.doi.org/10.1177/026635119701200306.
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Seismic isolation and fuzzy vibration control systems, which consist of a shell with an edge beam which has springs and variable dampers between the edge beam and the ground, are suggested by one of the authors. In this paper, natural vibration modes and natural frequencies of base isolated rotational shells with edge beams are shown. When the shell shakes due to vertical seismic forces, the seismic isolated system is implemented. As a result, stresses in the shell are significantly reduced. Furthermore, vibration control of the shell is carried out. Then the damping ratios are adjusted by the fuzzy theory, and stresses in the shell are further reduced.
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Kim, Habeom, Hyunsoo Lee, and Gyoung-Ah Lee. "NEW MARINE RESERVOIR CORRECTION VALUES (ΔR) APPLICABLE TO DATES ON NEOLITHIC SHELLS FROM THE SOUTH COAST OF KOREA." Radiocarbon 63, no. 4 (June 28, 2021): 1287–302. http://dx.doi.org/10.1017/rdc.2021.45.
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ABSTRACTShells from Neolithic shell midden sites have been routinely dated in Korea, but they have not been calibrated based on the correction values (ΔR) for the marine reservoir effect (MRE). A lack of proper calibration has left dates on shells incomparable to those on terrestrial samples, and thus unusable in building the chronological sequence of shell middens. Here, we report the two new ΔR values of a pre-bomb (pre-1950) blue mussel from the south coast. We applied the two new and the two previously reported ΔR values to the three dates on marine shells from the Bibongri shell midden in southeastern Korea. Our ΔR adjusted calibration and the comparison to dates on charcoal and bone remains clarify an ambiguity in the stratigraphy and the Early Neolithic chronology at Bibongri. Our contribution is to provide the ΔR values that can be further applied to other Neolithic shell middens along the south coast.
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Kylili, Angeliki, and Paris A. Fokaides. "A High Performance Controlled Temperature Building Shell for the Sustainable Upgrading of Buildings." Procedia Environmental Sciences 38 (2017): 130–39. http://dx.doi.org/10.1016/j.proenv.2017.03.094.
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Ochoa, Jessica M., Oscar Mijares, Andrea A. Acosta, Xavier Escoto, Nancy Leon-Rivera, Joanna D. Marshall, Michael R. Sawaya, and Todd O. Yeates. "Structural characterization of hexameric shell proteins from two types of choline-utilization bacterial microcompartments." Acta Crystallographica Section F Structural Biology Communications 77, no. 9 (August 24, 2021): 275–85. http://dx.doi.org/10.1107/s2053230x21007470.
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Bacterial microcompartments are large supramolecular structures comprising an outer proteinaceous shell that encapsulates various enzymes in order to optimize metabolic processes. The outer shells of bacterial microcompartments are made of several thousand protein subunits, generally forming hexameric building blocks based on the canonical bacterial microcompartment (BMC) domain. Among the diverse metabolic types of bacterial microcompartments, the structures of those that use glycyl radical enzymes to metabolize choline have not been adequately characterized. Here, six structures of hexameric shell proteins from type I and type II choline-utilization microcompartments are reported. Sequence and structure analysis reveals electrostatic surface properties that are shared between the four types of shell proteins described here.
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Leung, Jonathan Y. S., Zoë A. Doubleday, Ivan Nagelkerken, Yujie Chen, Zonghan Xie, and Sean D. Connell. "How calorie-rich food could help marine calcifiers in a CO 2 -rich future." Proceedings of the Royal Society B: Biological Sciences 286, no. 1906 (July 10, 2019): 20190757. http://dx.doi.org/10.1098/rspb.2019.0757.
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Increasing carbon emissions not only enrich oceans with CO 2 but also make them more acidic. This acidifying process has caused considerable concern because laboratory studies show that ocean acidification impairs calcification (or shell building) and survival of calcifiers by the end of this century. Whether this impairment in shell building also occurs in natural communities remains largely unexplored, but requires re-examination because of the recent counterintuitive finding that populations of calcifiers can be boosted by CO 2 enrichment. Using natural CO 2 vents, we found that ocean acidification resulted in the production of thicker, more crystalline and more mechanically resilient shells of a herbivorous gastropod, which was associated with the consumption of energy-enriched food (i.e. algae). This discovery suggests that boosted energy transfer may not only compensate for the energetic burden of ocean acidification but also enable calcifiers to build energetically costly shells that are robust to acidified conditions. We unlock a possible mechanism underlying the persistence of calcifiers in acidifying oceans.
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Zhong, Kuo, Kai Song, and Koen Clays. "Hollow spheres: crucial building blocks for novel nanostructures and nanophotonics." Nanophotonics 7, no. 4 (March 28, 2018): 693–713. http://dx.doi.org/10.1515/nanoph-2017-0109.
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AbstractIn this review, we summarize the latest developments in research specifically derived from the unique properties of hollow microspheres, in particular, hollow silica spheres with uniform shells. We focus on applications in nanosphere (colloidal) lithography and nanophotonics. The lithography from a layer of hollow spheres can result in nanorings, from a multilayer in unique nano-architecture. In nanophotonics, disordered hollow spheres can result in antireflection coatings, while ordered colloidal crystals (CCs) of hollow spheres exhibit unique refractive index enhancement upon infiltration, ideal for optical sensing. Furthermore, whispering gallery mode (WGM) inside the shell of hollow spheres has also been demonstrated to enhance light absorption to improve the performance of solar cells. These applications differ from the classical applications of hollow spheres, based only on their low density and large surface area, such as catalysis and chemical sensing. We provide a brief overview of the synthesis and self-assembly approaches of the hollow spheres. We elaborate on their unique optical features leading to defect mode lasing, optomicrofluidics, and the existence of WGMs inside shell for light management. Finally, we provide a perspective on the direction towards which future research relevant to hollow spheres might be directed.
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Abramczyk, Jacek, and Aleksandra Prokopska. "Symmetric Shape Transformations of Folded Shell Roofs Determining Creative and Rational Shaping of Building Free Forms." Symmetry 11, no. 12 (November 22, 2019): 1438. http://dx.doi.org/10.3390/sym11121438.
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The paper presents an innovative approach to solving interdisciplinary problems emerging in the design process of building free forms roofed with elastically transformed corrugated shells. The effectiveness and rationality of shaping such free forms and the creativeness in searching for the parametric forms require the application of their regular and symmetric models which have to be derived from the geometric and mechanical properties of the rationally transformed subsequent folds of these shells. Simplified smooth models used for engineering developments and accurate folded models implemented for scientific research have to be created by means of unconventional methods different from those presented in classical courses. Owing to the variety of the forms of the proposed innovative reference tetrahedrons and their parametric description, the algorithms developed by the authors have to be implemented in computer programs. The rationality of the transformed roof shells, revealed in the limitation of the level of the fold’s initial stresses resulting from the shape transformation, and the attractiveness of these forms are achieved by the axial symmetry and contraction of each shell fold at its half-length. The symmetries adopted in the process of modeling such roof shells are also exploited by the discussed new method to obtain coherent unconventional general forms of entire buildings.
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Yamamoto, Tetsuo, and Koji Yoshida. "Development of Automatic Shell Building System for LEVICAST." DENKI-SEIKO[ELECTRIC FURNACE STEEL] 68, no. 3 (1997): 205–11. http://dx.doi.org/10.4262/denkiseiko.68.205.
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Ko, Soo-Min, and Jae-Hoon Kang. "Vibration of Hemispherical-Cylindrical-Hemispherical Shells and Complete Hollow Spherical Shells with Variable Thickness." International Journal of Structural Stability and Dynamics 19, no. 03 (March 2019): 1950018. http://dx.doi.org/10.1142/s0219455419500184.
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The natural frequencies and mode shapes of enclosed shell typed structures with variable thickness (hemispherical-cylindrical-hemispherical shells and complete hollow spherical shells) are determined by the Ritz method using a three-dimensional (3D) analysis. However, in the conventional shell analysis, mathematically two-dimensional (2D) thin shell theories or higher order thick shell theories are often employed, which adopt limiting assumptions about the displacement variation through the shell thickness. While most researchers have adopted the 3D shell coordinates that are normal and tangential to the shell mid-surface, the present analysis is based upon the circular cylindrical coordinates. By the Ritz method, the Legendre polynomials, which are mathematically orthonormal and minimal, are used as the admissible functions, instead of the ordinary algebraic polynomials. The strain and kinetic energies of the combined shell structures are formulated, and upper bound solutions of the frequencies are obtained by minimizing the solution for frequencies. As the degree of the Legendre polynomials is increased, frequencies converge to the exact values. Convergence to four-digit exactitude is demonstrated for the first five frequencies. The frequencies from the present 3D method are compared with those from other 3D approach and 2D thin and thick shell theories existing in the literature. The present 3D analysis is applicable to both very thick shells and very thin shells.
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Schmidt, Herbert. "Two decades of research on the stability of steel shell structures at the University of Essen (1985–2005): Experiments, evaluations, and impact on design standards." Advances in Structural Engineering 21, no. 16 (March 6, 2018): 2364–92. http://dx.doi.org/10.1177/1369433218756273.
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In this article, the author looks back on the shell buckling research activities during his 20 years as Full Professor for Steel Structures at the University of Essen, Germany. The main research projects of that time are described very shortly. They included unstiffened circular cylindrical shells under external pressure or meridional compression or combined loading, made of structural or stainless steel at ambient or high temperatures, optionally with wall openings. Stiffened circular cylindrical shells under external pressure or meridional compression were also dealt with, as well as unstiffened conical shells, either as part of cone/cylinder assemblies or as individual truncated cones. Furthermore, the special case of very thin-walled open cylindrical tank shells was investigated under axisymmetric external pressure or wind-like pressure distribution or transverse shear. All projects combined realistic experiments on steel specimens with comparative or enhancing numerical investigations, and all of them were aimed at contributing directly to the improvement of practical shell stability design rules. Last but not least, it is reported on early efforts to develop guidelines for shell buckling design by global numerical analysis, and the author’s credo argued that physical experiments are still indispensable in practice-oriented structural research, particularly in a complex field like shell stability. The article has been written in honor of John Michael Rotter, Professor Emeritus of the University of Edinburgh, who will celebrate his 70th birthday in October 2018.
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Tabunshchikov, Yuri, and Marianna Brodach. "OPTIMIZATION PROBLEMS OF MATHEMATICAL MODELLING OF A BUILDING AS A UNIFIED HEAT AND POWER SYSTEM." International Journal for Computational Civil and Structural Engineering 16, no. 1 (March 24, 2020): 156–61. http://dx.doi.org/10.22337/2587-9618-2020-16-1-156-161.
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The mathematical model of a building as a single heat energy system by the decomposition method is represented by three interconnected mathematical models: the first is a mathematical model of the energy interaction of a building’s shell with an outdoor climate; the second is a mathematical model of energy flows through the shell of a building; the third is a mathematical model of optimal control of energy consumption to ensure the required microclimate. Optimization problems for three mathematical models with objective functions are formulated. Methods for solving these problems are determined on the basis of the calculus of variations and the Pontryagin maximum principle. A method for assessing the skill of an architect and engineer in the design of a building as a single heat energy system is proposed.
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Mols, Toms, and Andra Blumberga. "Inverse Modelling of Climate Adaptive Building Shells. System Dynamics Approach." Environmental and Climate Technologies 24, no. 2 (September 1, 2020): 170–77. http://dx.doi.org/10.2478/rtuect-2020-0064.
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AbstractThe paper describes the development of a computer-based inverse model for climate adaptive building shell which is in the cold climatic conditions of Latvia to determine changes in energy consumption. Types, principles of operation and classification of climate adaptive building shells (CABS) were reviewed and CABS most fitting to Latvia’s climate conditions were chosen for application in the model. Research implies that building modelling tools play an important role in the design phase. The results indicate that hourly facade adjustment can have a significant impact on GHG emissions and energy consumption reduction without compromising the comfort level. Optimization is proven to be an essential part of the inverse modelling phase, which provides the best possible option defined by the user for the characteristics that distinguish climate adaptive building shells. Inverse modelling approach allowed to determine necessary building enclosure parameters that need to be met to provide best performance.
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Stupishin, Leonid U., and Alexander G. Kolesnikov. "Reconstruction of Shallow Shells for Increase Bearing Capacities and Operating Characteristics." Applied Mechanics and Materials 580-583 (July 2014): 3062–65. http://dx.doi.org/10.4028/www.scientific.net/amm.580-583.3062.
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Bearing capacities and operating characteristics cover of a building deteriorate since time. Reconstruction of shallow shells cover by increase of their thickness in the center or at the edge. Critical force and stress of shell are considered with the geometric nonlinearity consideration. Vertical static loading and various types of a fixing are investigated. The method allows to describe various forms of shells with defects.
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Anu S Das, Ansu V, Megha P, Nithin M Thomas, and Sachin A K. "Assessment of Strength of Hollow Concrete Blocks with Holes Reinforced with Half Portion of Coconut Shells." Journal on Today's Ideas - Tomorrow's Technologies 6, no. 2 (December 25, 2018): 93–98. http://dx.doi.org/10.15415/jotitt.2018.62008.
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Natural building materials are diminishing day by day. Hence economical alternatives of natural building materials are necessary for sustainable development. Hollow concrete block was developed to reduce the use of natural building materials. Agricultural waste products like coconut shells from coconut industry have disposal problems causing environmental concerns. Various studies were done in the past, replacing a portion of the natural aggregates with broken coconut shells for manufacturing the hollow concrete blocks. In this study, we have developed a new method of forming the holes of hollow concrete blocks by placing stacks of half portion of coconut shells at the bottom with convex surface upwards to reinforce the holes by arch action. The results show that the coconut shell reinforced hollow concrete blocks have better strength as compared to open-graded hollow concrete blocks available in the market.
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Piontek, Marlena, Katarzyna Łuszczyńska, and Hanna Lechów. "Technological Moisture as a Cause of Moulds on Building Partitions." Civil and Environmental Engineering Reports 28, no. 2 (June 1, 2018): 76–84. http://dx.doi.org/10.2478/ceer-2018-0020.
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Abstract The intense pace of construction work means that technical materials contain so-called technological moisture, which enables the development of biodeteriogenic organisms on building partitions. This article presents the mycological analysis of two buildings in Zielona Góra, whose building partitions were affected by colour deposits. In the first building (a block of flats in the shell and core condition) 7 species of moulds were determined, of which the dominant one was Cladosporium herbarum. In the second building (public utilities building) changes on the walls appeared just after refurbishment and were caused by a species of mould called Strachybotrys chartarum which is hazardous to human and animal life.
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Lusis, Vitalijs. "Formwork with Variable Geometry for Concrete Shells Production Technology." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 2 (August 8, 2015): 63. http://dx.doi.org/10.17770/etr2013vol2.855.
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One of the main constructive materials in the building sphere is a precast concrete and fiber concrete. It is well influenced by scientific research basis, development and implementation of progressive technologies. The fiber concrete it is an ideal material with practically unlimited number of shapes. A nomenclature of concrete articles increases, it is working on different shape formation and processing. While preparation for this document started with the concept fabrication, it is necessary to understand the methods of construction variable geometry formwork of concrete thin-shell surfaces, both past and present as a point of departure. An understanding of this background helps provide an essential foundation for the exploration of new potential advances in the field of thin-shell construction. Obviously that is the reason for fiber concrete to be the most widespread constructive building material all over the world. In the article are considered shell development technology features and is evaluated technical and economical effectiveness of concrete shells with thin walls. Now variable geometry systems from flexible materials are developing and improving, there is a great potential followed by modern events in concrete technology. The results of laboratory experiments have proved that the technology can be used for fibro concrete shell production and construction.
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Sadygov, I. "FREE AND FORCED VIBRATIONS OF SHELLS OF VARIOUS SHAPES, TAKING INTO ACCOUNT THE VARIABILITY OF THE NON-LINEAR ELASTIC MATERIAL." Construction Materials and Products 3, no. 1 (July 8, 2020): 70–75. http://dx.doi.org/10.34031/2618-7183-2020-3-1-70-75.
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the article considers issues of shell vibrations, which are widely used in various industries and construction. Shells serve as elements of building structures with large spans.
The chapter “Introduction” discussed issues related to the use of shells in all areas of industry, in aviation, rocket and space technology, railway transport, in the oil and gas industry and provides examples of shells for use in ceilings of circuses, stations, hangars; in industry: shells of rotation used as tanks, containers, columns, reactors, etc. In the section “Materials and research methods” free and forced vibrations of shells of variable thickness made out of nonlinear elastic material reviewed. In shell calculations the Kirchhoff – Law hypothesis was used. It was found that, during vibrations, the shells experience relative deformation of elongation and shear of the surface with coordinates (x, y), as well as bending and torsion strains. It is established that vibrations in the shells lead to a rotation of the main directions of elasticity and regarding to the adopted coordinate axis to angle θ, and the elastic constants of the material depend on the elastic constant Biy – the main directions of the nonlinear elastic shells.
When solving the system of equations of motion of the shell relative to the displacements arising in it during vibration, based on theory R and various methods. The values of the dimensionless frequency parameter for a spherical shell taking into account changes in its curvature, variability and thickness of elastic properties are obtained.
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Prokopska, Aleksandra, and Jacek Abramczyk. "Innovative Building Forms Determined by Orthotropic Properties of Folded Sheets Transformed Into Roof Shells." Journal of the International Association for Shell and Spatial Structures 61, no. 2 (June 1, 2020): 111–24. http://dx.doi.org/10.20898/j.iass.2020.204.044.
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Qualitative and quantitative characteristics of geometrical and mechanical changes of nominally plane steel sheets folded in one direction, caused by big elastic shape transformations were invented on the basis of the authors' tests, analyzes and computational models of thin-walled folded sheets transformed into shell shapes. Both geometrical and mechanical changes produce significant restrictions in using sheets for shell forms. The deliberate transformations and sheets' characteristics are required to obtain attractive and innovative forms of roof shells and their consistent structures as well as entire buildings. The search for effective solutions related to free forms of buildings and shape transformations of sheets especially in the fields of: shape transformation, effort and stabilization of their walls is necessary due to the high sensitivity of thin-walled open profiles to boundary conditions and loads. A method for shaping such free form buildings that effectively exploit specific orthotropic properties of the transformed sheeting is presented.
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Sadiq, Obanishola M. "Dynamic Response of Complete Torospherical Shells under Internal Periodic Pressure." Advances in Structural Engineering 3, no. 3 (July 2000): 181–90. http://dx.doi.org/10.1260/1369433001502139.
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The study reported here is concerned with the response of complete Torospherical shells under internal dynamic pressure. The Torospherical shell modelled from an Ellipsoidal shell consists of a combination of spherical segments joined with toroidal segments of circular cross-section. The nonlinear systems of dynamic equations formulated were solved using trigonometric projection procedures and Newton's iterative processes. Two types of torospherical shells were analysed and compared. Results show that the dynamic response of the Torospherical shells subjected to internal dynamic pressure depends not only on the frequency of dynamic pressure but specifically on the ratio of the radii of the toroidal segments to that of the spherical segments. We also discovered that if loss of dynamic stability of ellipsoidal shells is largely axisymmetrical, loss of dynamic stability of Torospherical shells is asymmetrical with formation of circular waves in the circumferential direction. The modes of vibration of the Torospherical shells are also presented.
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Huang, H., M. Michelini, M. Schmitz, L. Roth, and H. Mayer. "LOD3 BUILDING RECONSTRUCTION FROM MULTI-SOURCE IMAGES." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B2-2020 (August 12, 2020): 427–34. http://dx.doi.org/10.5194/isprs-archives-xliii-b2-2020-427-2020.
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Abstract. We propose a pipeline for the detection as well as modeling of individual buildings based on multi-source images. It allows to consistently reconstruct whole buildings at Level of Detail 3 (LoD3): the roof from airborne images and the facades including elements such as windows and doors mainly from terrestrial images. We employ a parametrized top-down model – the “shell model” – with the roof as well as the facades semantically and geometrically integrated. This generative model fosters stability for building detection by enabling the use of multi-source data and offers flexibility in modeling by means of a fully CAD-compatible integration of building components. Experiments performed on imagery from different terrestrial and airborne (Unmanned Aerial Vehicle – UAV) cameras demonstrate the potential of the approach.
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Doerich, Cornelia, Margi Vilnay, and J. Michael Rotter. "Strength determination for band-loaded thin cylinders." Advances in Structural Engineering 21, no. 16 (July 20, 2018): 2454–65. http://dx.doi.org/10.1177/1369433218787715.
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Cylindrical shells are often subjected to local inward loads normal to the shell that arise over restricted zones. A simple axisymmetric example is that of the ring-loaded cylinder, in which an inward line load around the circumference causes either plasticity or buckling. The ring-loaded cylinder problem is highly relevant to shell junctions in silos, tanks and similar assemblies of shell segments. The band load is similar to the ring load in which a band of inward axisymmetric pressure is applied over a finite height. When the height is very small, the situation approaches the ring-loaded case, and when the height is very large, it approaches the uniformly pressurised case. This article first thoroughly explores the two limiting cases of plastic collapse and linear bifurcation buckling, which must both be fully defined before a complete description of the nonlinear and imperfection-sensitive strengths of such shells can be described within the framework of the European standard for shells (EN 1993-1-6). Finally, the application of the reference resistance design (RRD) over the complete range of geometries for the perfect structure is shown using the outcome of the limiting cases.
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Ren, Xiaodan, Weida Fan, Jie Li, and Jun Chen. "Building Information Model–based finite element analysis of high-rise building community subjected to extreme earthquakes." Advances in Structural Engineering 22, no. 4 (June 18, 2018): 971–81. http://dx.doi.org/10.1177/1369433218780484.
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Starting from the Building Information Model, a pre-processing procedure is proposed in this work to develop the refined finite element model of buildings and building community. The structural members which are represented by three-dimensional solid entities in Building Information Model are converted to lines and planes according to their geometric characteristics. To meet the requirements of finite element analysis of building structures, the lines are discretized by the beam elements and the surfaces are discretized by the shell elements. The damage plasticity model is implemented to simulate the damage and failure of concrete, and the classic plasticity model is chosen for steel. The simulations of high-rise building and building community are performed with the help of large computing server. The damage patterns of different building structures are obtained and discussed. This study lays a solid foundation for the further fusion between Building Information Model and finite element analysis.
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Li, Yuan-Qi, and Zu-Yan Shen. "Arch-Supported Reticulated Shell Structures and Their Static Mechanical Behaviour." International Journal of Space Structures 17, no. 4 (December 2002): 263–69. http://dx.doi.org/10.1260/026635102321049529.
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Based on the structural features of reticulated shells, arch structures, etc., arch-supported reticulated shell structures have been developed as a new large-span space structural system. In the paper, the acceptability of this hybrid structural system and the reasonable combination of arch structures and reticulated shells with different Gaussian curvatures are discussed. Several ideas on using arch-supported reticulated shell structures to form openable structures are also mentioned. Compared to single-layer reticulated shells, the mechanical behaviour of the hybrid structures, especially the influence of initial geometrical imperfection, was investigated through nonlinear analysis and experimental research on three typical models. Analysis indicates that hybrid structures can efficiently decrease the geometrical imperfection sensitivity and improve their integral mechanical behaviour, which proves that this type of hybrid structures can be used widely.
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Sahoo, Sarmila. "Free Vibration of Laminated Composite Hypar Shell Roofs with Cutouts." Advances in Acoustics and Vibration 2011 (December 25, 2011): 1–13. http://dx.doi.org/10.1155/2011/403684.
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Use of laminated composites in civil engineering structural components including shell roofs is increasing day by day due to their light weight, high specific strength, and stiffness properties. In the present paper, laminated composite hypar shell (hyperbolic paraboloidal shells bounded by straight edges) roofs with cutouts are analyzed for their free vibration characteristics using finite element method. An eight-noded curved shell element is used for modeling the shell. Specific numerical problems of earlier investigators are solved to compare their results with the present formulation. A number of problems are further solved where the size of the cutouts and their positions with respect to the shell centre are varied for different edge constraints. The results are furnished in the form of figures and tables. The results are examined thoroughly to arrive at some meaningful conclusions useful to designers.
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Abramczyk, Jacek, and Aleksandra Prokopska. "Parametric Creative Design of Building Free-forms Roofed with Transformed Shells Introducing Architect’s and Civil Engineer’s Responsible Artistic Concepts." Buildings 9, no. 3 (March 6, 2019): 58. http://dx.doi.org/10.3390/buildings9030058.
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The article concerns a parametric description of unconventional building forms roofed with folded sheeting transformed elastically into shells. The description supports the designer in the search for attractive forms and a rational use of materials. The adoption of strictly defined sets of initial parameters determines the diversification of the designed architectural free-forms. An impact of selected proportions between these parameters on these forms is illustrated by an example of a single structure. Folded elevations and a segmented shell roof make each such structure internally coherent and externally sensitive. The mutual position and proportions of the shape of all elements, such as the roof, eaves, and façades, along with regular patterns in the same structure, determine this consistency of its form and sensitivity to harmonious incorporation into the natural or built environments. The study is a new insight into shaping free-forms of buildings in which the modern and ecological materials determine the important shape and mechanical limitations of these forms. With a skillful approach, the materials allow their extensive use in buildings. However, various interdisciplinary problems related to architectural shaping of free-forms and static and strength work thin-walled shell sheeting roofs must be solved. For effective design it is necessary to use relevant software applications, where spatial reasoning is crucial for ordering the three-dimensional space by means of simplified engineering models.
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Kang, Jae-Hoon. "3D Vibration Analysis of Combined Shells of Revolution." International Journal of Structural Stability and Dynamics 19, no. 02 (February 2019): 1950005. http://dx.doi.org/10.1142/s0219455419500056.
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A three-dimensional (3D) method of analysis is presented for determining the natural frequencies and the mode shapes of combined hemispherical–cylindrical shells of revolution with and without a top opening by the Ritz method. Instead of mathematically two-dimensional (2D) conventional thin shell theories or higher-order thick shell theories, the present method is based upon the 3D dynamic equations of elasticity. Mathematically, minimal or orthonormal Legendre polynomials are used as admissible functions in place of ordinary simple algebraic polynomials which are usually applied in the Ritz method. The analysis is based upon the circular cylindrical coordinates instead of the shell coordinates which are normal and tangent to the shell mid-surface. Strain and kinetic energies of the combined shell of revolution with and without a top opening are formulated, and the Ritz method is used to solve the eigenvalue problem, thus yielding upper bound values of the frequencies by minimizing the frequencies. As the degree of the Legendre polynomials is increased, frequencies converge to the exact values. Convergence to four-digit exactitude is demonstrated for the first five frequencies. Numerical results are presented for the combined shells of revolution with or without a top opening, which are completely free and fixed at the bottom of the combined shells. The frequencies from the present 3D Ritz method are compared with those from 2D thin shell theories by previous researchers. The present analysis is applicable to very thick shells as well as very thin shells.
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XIANG, Y., C. W. LIM, and S. KITIPORNCHAI. "AXISYMMETRIC VIBRATION OF CYLINDRICAL SHELLS WITH INTERMEDIATE RING SUPPORTS." International Journal of Structural Stability and Dynamics 03, no. 01 (March 2003): 35–53. http://dx.doi.org/10.1142/s021945540300080x.
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This paper treats the axisymmetric vibration of thin circular cylindrical shells with intermediate ring supports based on the Goldenveizer–Novozhilov thin shell theory. An analytical method is proposed, and new exact solutions are presented to study the axisymmetric vibration characteristics of the ring supported cylindrical shells. In the proposed method, the state-space technique is employed to derive a homogenous differential equation system for a shell segment, and a domain decomposition approach is developed to cater for the continuity requirements between shell segments. Exact frequency parameters are presented for circular cylindrical shells that have multiple intermediate ring supports and various combinations of end support conditions. These exact vibration frequencies may serve as important benchmarks against which researchers can validate their numerical methods for such circular cylindrical shell problems.
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Christian, John, and George Kallouris. "An expert system for predicting the cost – time profiles of building activities." Canadian Journal of Civil Engineering 18, no. 5 (October 1, 1991): 810–17. http://dx.doi.org/10.1139/l91-098.
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This paper describes the development of a prototype knowledged-based expert system for predicting the cost – time profiles of various construction activities in New Brunswick. Knowledge, both quantitative and qualitative, about the cost – time patterns of various activities in educational, office, and apartment building projects in New Brunswick are stored in an expert system shell (Personal Consultant Plus). The system simulates a consultation between an expert and a user, where the microcomputer represents the expert and the user is the prospective building contractor or owner. The output of the consultation shows how the total cost of the various trades will most likely be distributed over time. This will enable the contractor and the client to anticipate the probable financial commitments each month, even before any schedule is available, once an investment decision has been made. Funds can then be arranged in such a way as to match the progress of work and therefore meet the financial demands of each individual building activity. Key words: cost – time profiles prediction, expert system, shell, knowledge base, buildings, construction, rules, parameters.