【正文】 and Lt1Dt m 5 current length of member m at time, calculated using Pythagoras’s theorem in three dimensions. This process is continued, cycle by cycle, to trace the motion of the structure. So far, no damping has been introduced and, thus, the grid continues to oscillate. This phenomenon can be prevented by introducing ―kiic damping‖ in all the velocities that are set to zero when a kiic energy peak is detected. This process will never truly converge, but once the residual forces are measured in, for example, thousandths of Newtons, convergence has occurred for all practical purposes. At that point, a shape is found that is in static equilibrium and that holds the ―correct‖ spatial surface. This formfinding process yields a 3D cupola with a height of m, as shown in Fig. 5 (ratio height/span 5 ). The steel skeletal shell mainly works in pression under selfweight. As to be expected, large tensile forces arise in the ring beam framing the shell. The structural elements radiating out from the corners experience the largest pressive forces. Although all boundary nodes can transmit vertical forces onto the fa231。 Planarity faces。外殼 的 制造和施工在 2021 年和 2021 年之間。 薄膜效 應(yīng)使材料的性能得以充分發(fā)揮 。 當(dāng)然，這也 一直 受到立體 解析幾何和設(shè)計者想象力 強加的 規(guī)則 的 限制。 其限制條件通常包括高度的限制以及強加于現(xiàn)有建筑物 ,尤其是水平方向，最大負(fù)荷的限制。 十九世紀(jì)中期 ， 溫室類型學(xué)已全面發(fā)展，由此便產(chǎn)生了文化室、暖房以及冬景花園 [例如 , 皇家溫室、拉肯 ,比利時 (建于 1876 年 )現(xiàn)于 Fig. 1 (Woods and Swartz 1988)].冬季花園 是本文特別感興趣的 ,因為它 是 一個社交場合 ，與 一 棟私人豪宅或公共建筑 及其接近 。屋頂 。 and Chris Williams4 摘要 :在對 荷蘭阿姆斯特丹荷蘭海事博物館 頂部覆蓋的 一種高效的結(jié)構(gòu) 形式進(jìn)行探究的文章中，作者 簡要討論 了作用力對 最早的玻璃屋頂覆蓋物 的 影響。 DOI: /(土木 ) 。麥克斯韋互惠網(wǎng)絡(luò)。 頂部覆蓋玻璃 的單層鋼骨架的形狀由雕塑、幾何、物理以及施工條件等因素共同決定。 然而， 設(shè)計師往往忽略 這樣 一個事實 ,即 建筑物 自由 的結(jié)構(gòu) 形式由傳統(tǒng)的 建筑和結(jié)構(gòu)方式 構(gòu)造產(chǎn)生 。 他們設(shè)計 了 將屋面 分為平面四邊形網(wǎng)格 方法 ， 能夠 獲得 正確的 移動 型屋面 ,和 大小 可 變型 屋 面 。布勞克 和 奧科申朵夫 (2021)發(fā)表了 應(yīng) 力網(wǎng)絡(luò)分析 來 確定 純 壓力體系 。 Historic sites。 architect Massimiliano Fuksas, structural engineers Schlaich Bergermann and Partner and Mero TSK Group) illustrates how a sculptural shell is discretized in foursided and triangulated (at the supports) meshes Fig. 3. Hippo House (Germany, built in 1997), designed by architect Grieble and Schlaich Bergermann and Partners, shows the discretization of a translational surface into planar quadrangular meshes (photograph courtesy of Edward Segal, reprinted with permission) a fine structural work (skeleton) of individual small subelements. The first design consideration lies in setting the exact boundary conditions within which the shell shape can be developed. The curved shape is of vital importance to achieve stability through membrane stiffness. Shell bending needs to be avoided by finding the ―right‖ geometry, so that under the selfweight only membrane action results. Membrane action makes efficient use of material. The important structural design challenge lies in the determination of a threedimensional (3D) surface that will hold the skeletal shell. In the twentieth century, both architects and engineers [Gaudi (Huerta 2021), Otto (Otto et al. 1995), and Isler (Billington 2021)] experimented with physical form finding techniques, which for a given material, created a set of boundary conditions and gravity loading that found the efficient 3D structural shape. The importance of finding a funicular shape for steel shells lies in the fact that the selfweight (gravity loads caused by steel and glass) contributes largely to the load to be resisted. The subelements need to be loaded axially to make most efficient use of the section profile. Numerical form finding techniques [force density (Schek 1974) and dynamic relaxation (Day 1965)] have been successfully applied to weightless systems whose shape is set by the level of internal prestress and boundary supports. However, when it es to funicular systems whose shape is not determined by initial prestress but by gravity loads (such as the case for masonry, concrete, or steel shells), fewer numerical methods have been developed. This is mainly because of the difficulty of finding optimal forms for those shells that rely on both tensile and pressive membrane stresses to resist dead load. Kilian and Ochsendorf (2021) presented a shapefinding tool for statically determinate systems based ona particlespring system solved with a RungeKutta solver, used in puter graphics for cloth simulation. Block and Ochsendorf (2021) published the thrust work analysis to establish the shape of pure pression systems. For the initial design petition for the Dutch Maritime Museum roof project, the dynamic relaxation method usually used for prestressed systems was adapted to deal with 3D funicular systems with tension and pression elements under gravity loads. Competition Design for a Steel Glass Shell over the NSA Courtyard The Dutch Maritime Museum planned a thorough museum renovation in the near future. The restricted space in the seventeenth century historic building hinders the movement of visitors. The courtyard needed to be integrated into the museum’s circulation space, sheltered from weather, and kept to a minimal indoor temperature. An invited design petition was held for a new glass roof that added value to the historic building. In 2021, Ney and Partners, a Brusselsbased engineering design consultancy, won this petition with a steel and glass shell design. The shell manufacturing and construction processes took place between 2021 and 2021. In 2021, the project was awarded the Amsterdam Architectural Prize. Initial Planar Geometry In the late seventeenth century, the historic building housing the museum (shown in Fig. 4) was the headquarters of the admiralship. It was the instrument and symbol of the Dutch maritime power. The development of this seafaring nation was closely linked to the production of sea charts and the associated sciences, such as geometry, topography, and, astronomy. The classic building al