Stress oriented folded structures - an optimized light weight construction principle

由薄板组成的测地线穹顶是空间折叠结构的典型代表。由于它们的球形，它们的几何复杂性可以很容易地控制。在计算机图形学方法、参数软件和接口技术的帮助下，如今的空间折叠结构可以被生成和结构加工成自由形状的大型形状。通过添加空间褶皱并将其与平面表面元素相结合，可以生成一个轻质系统，该系统以这些褶皱和曲面作为其基本结构或其折叠核心。同时，该基本结构可用于近似确定自由形状。基本材料是薄的半成品，如钢板或纤维增强塑料。由于创新的成型技术，这些材料是可折叠的，因此可以用来建立新的轻质结构。对夹层结构中板状结构的参数研究证明了它们的有效性--以较轻的自重获得高承载能力。可以预期的是，通过使折叠结构的几何形状适应主要载荷情况的载荷，可以优化这些质量特性。虽然具有恒定折叠几何形状的褶皱可以通过标准的交联法生成，但以载荷为导向的褶皱的生成首先需要计算主应力。应力轨迹可以由计算的矢量场确定，它构成了镶嵌和后续折叠的基础。在这个过程中，对载荷的局部适应完全是由折叠频率和折叠高度等几何参数的变化造成的。例如，与负载较少的区域相比，负载较高的区域将具有更高的折叠频率和更大的折叠高度。通过计算主要荷载工况的主应力以及分析所生成的折叠结构的承载能力，需要考虑几何和可能的物理非线性。所有的板和折叠单元都是基于由原始曲面组成的网，这是有效实现的有利前提。然而，为了有效地制造，建议通过反多样化优化来最小化几何上不同的元件的数量。通过略微偏离原始几何形状和折叠元件接触区域的公差，可以组成相似的建筑元件组。本研究旨在分析负载导向的金属板材轻量化系统的基本原理和基本技术特点。计算机图形内容和静态结构内容的交替发展需要建筑学和计算机科学研究单位的合作。

Geodesic domes with their facets composed of thin sheet metal are impressive representatives of the category spatial folding structures. Due to their spherical shape, their geometrical complexity can be controlled easily. Thanks to computer-graphic methods, parametric software and interface-techniques, nowadays spatial folding structures can be generated and structurally processed as freely shaped large scale forms. By adding spatial foldings and combining them with planar surface elements a light weight system can be generated, that uses these foldings and surfaces as its basic structure or its folded core. At the same time, this basic structure can be used to approximately determine a freely shaped form. Basic materials are thin, semi-finished goods like steel-sheet or fiber-reinforced plastics. Due to innovative forming techniques, these materials are foldable and can therefore be used to establish novel light weight constructions. Parameter studies with slab-like constructions in sandwich structure with planar covers, a folded core and a constant folding geometry prove their efficiency - a high bearing capacity at a light dead weight. It is to be expected, that these quality characteristics can be optimized by adapting the geometry of the folding construction to the loading of the dominant load case. While foldings with a constant folding geometry can be generated via standard cross-linking algorithms, the generation of load-oriented foldings requires at first the calculation of the main stress. Stress trajectories, which can be determined by the calculated vector field, form the basis for the tessellation and subsequent folding. In this process, the local adaption to the loading results solely from the variation of geometric parameters like the folding frequency and the height of the folding. For instance, areas with a high loading will have an elevated folding frequency and a greater folding height than less loaded areas. By calculating the main stress of the dominant load case as well as by analyzing the load-bearing capacity of the generated folding construction, geometrical and possible physical non-linearities need to be considered. All slab and folding elements are based upon nets made of primitive surfaces, which is a favorable precondition for an efficient implementation. However, to fabricate efficiently, it is advisable to minimize the number of geometrically different elements through anti-diversification-optimization. By slight deviations from the original geometry and tolerances in the contact areas of the folding elements, groups of similar building elements can be composed. This research application aims at analyzing the basic principles and fundamental technical characteristics of a load-oriented sheet-metal light weight system. The alternating development of computer-graphical and static-constructional contents necessitates the cooperation of architecture and computer sciences research units.