【正文】 用物理形式尋找這樣一種方法,在對于一個給定的材料,建立一組邊界條件和重力荷載,以尋找有效的三維結構形狀。子模塊需要軸向加載使截面輪廓最有效地受力。然而,當談到纜索系統(tǒng)的形狀并不取決于初始預應力而是由重力負載 (如案例中的磚石、混凝土或鋼殼) 決定時,更少的數(shù)值模擬方法被應用?；骱蛫W科申朵夫(2005) 為靜定系統(tǒng)呈現(xiàn)了一種基于粒子彈簧系統(tǒng)的面料仿真模型的結構形狀探索工具，該系統(tǒng)是用龍格庫塔求解器求解。對于荷蘭海事博物館屋頂?shù)某跏荚O計大賽項目, 動態(tài)松弛法通常是用于預應力系統(tǒng)，該法適應處理重力加載下，張力和壓力下的三維纜索體系。十七世紀歷史建筑成為受限空間阻礙了游客的運行。這樣，一個邀請設計大賽被舉辦，為這座歷史建筑增加更多附加價值一個新的玻璃屋頂產(chǎn)生了。外殼的制造和施工在2009年和2011年之間。Finding the Form of an Irregular Meshed Steel and Glass ShellBased on Construction ConstraintsSigrid Adriaenssens, 。 Eric Bodarwe3。 2012 American Society of Civil Engineers.CE Database subject headings: Design。 Glass。 Roofs。 Conceptual design。 Steel glass shell。 Planarity faces。Maxwell reciprocal network.IntroductionIn the wake of the Industrial Revolution, glass metal structuresappeared as a result of two factors: society’s desire for green, quietspaces in overpopulated cities, and the scientific emergence of newconstruction materials (glass and iron).In the early nineteenth century, the first greenhouses with aglazed roof appeared as living spaces. Their tall construction andmaintenance costs (because of the glass and the required heatingsystem) made them style icons of the elite. Their curved shapes[(1) ridge and furrow ., Chatsworth, United Kingdom (builtin 1834), and (2) vaulted, ., Kew, United Kingdom (built in1844) (Kohlmaier and Von Sartory 1991)] allowed the sparsesunlight into the space and hit the citrus and lime trees (hence, thename orangery). Other varieties of tender plants, shrubs, andexotic plants were also housed in the orangery. The introductionof the palm tree, an impressive and prestigious plant with largereligious significance, pushed the shape of the greenhouse furtherupwards.In the middle of the nineteenth century, the development ofgreenhouse typologies was in full swing, and resulted in culturehouses, conservatories, and winter gardens [., the Royal greenhouses,Laeken, Belgium (built in 1876) shown in Fig. 1 (Woods andSwartz 1988)]. The winter garden is of particular interest to thispaper because it defines a social meeting place adjacent to a privatemansion or public building.Mass production of affordable iron in the second half of thenineteenth century further encouraged the design and constructionof tall and large span exhibition halls made of cast and wrought ironand glass. Plenty of light entered the exhibition areas of buildings,such as the Crystal Palace, United Kingdom (built in 1851) (shownin Fig. 1). Its filigree iron structural skeleton was prefabricated, andit was subsequently dismantled and moved from Hyde Park toSydenham in South London. Unfortunately, it was destroyed by firein 1936.The second half of the 20th and the early 21st centuries experienceda new uprising of the design and construction of roofs oversocial gathering places, winter gardens without plants, coveringcourtyards of historically important public buildings [., the greatcourtyard of the British Museum, United Kingdom。 theDeutschen Historischen Museum, and Museum fur HamburgischeGeschichte, Germany (both Schlaich Bergermann and Partners, builtin 2001 and 2004, respectively)。 reprinted with permission fromthe photographer)。 (c) British Museum Courtyard (United Kingdom, built in 2000)steel roof adds value to the museum by expanding the useable circulationspace (image by authors)imposed existing situation, sculptural architectural esthetics,geometric shape, and structural efficiency through form.Imposition on an Existing Situation: The ModernWinter GardenIn the last two decades, existing historically relevant publicbuildings with a central open courtyard have been adapted to extendthe useable floor area to an indoor/outdoor climate. Thesegenerally narrow buildings count on the courtyard for daylight.Steel and glass shells offer a unique solution to this design challenge.The historic context for these shells imposes a series ofdesign constraints within which the designer has the freedom todevelop the shell’s form. The boundary conditions often includeheight restrictions and limits upon the maximumextra load that canbe imposed on the existing building, particularly in a horizontaldirection. The British Museum Court Roof is supported on slidingbearings so that no horizontal thrust is exerted on the historicmasonry walls of the museum (Williams 2001). In the reviewingthe design of recently realized steel shells, the driving design factormore often seems to be architectural scenographic esthetics ratherthan structural performance.Sculptural Architectural EstheticsWith the available geometric digital modeling tools, more architectsbase their work on esthetic (and often subjective) considerations toachieve scenographic effects. This sculptural design intent can beappreciated for its inventiveness of plastic forms, but not for itsconsideration of gravity loads. This particular design approach thusraises questions from a structural point of view with respect to theresulting lack of structural efficiency. Unfortunately, the structuralsolutions necessary to make these sculptural shapes possible typicallyuse an awkward and significant accumulation of material.These freeform shapes often lead to unfavorable internal forces andunder loading do not allow membrane stresses to develop within thesurface. These shapes then rely on bending action—the least effectiveof all basic load carrying methods. Designers often ignore thefact that the free form is made up of conventional constructional andstructural means. Frank Gehry, the Pritzker prizewinning architect,promotes this architectural process, which expresses sculpturalintentions but is disconnected from any sculptural intent (Shelden2002). A rationalization is needed at the preliminary design stagethat goes beyond this scenographic experience and concentrates onthe structural integrity of the design (Leach et al. 2004).