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Stress oriented folded structures - an optimized light weight construction principle

应力导向折叠结构 - 优化的轻质结构原理

基本信息

批准号：
269321250
负责人：
Professor Dr. Leif Kobbelt
金额：
--
依托单位：
Lehrstuhl für Tragkonstruktionen
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2017-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/269321250?language=en
关键词：
Stress oriented folded structures optimized

项目摘要

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.

由薄金属片组成的测地线圆顶是空间折叠结构的典型代表。由于它们的球形形状，它们的几何复杂性可以很容易地控制。由于计算机图形学方法、参数化软件和界面技术的发展，空间折叠结构可以被生成和处理成自由形状的大尺度结构。通过添加空间折叠并将它们与平面表面元素组合，可以生成使用这些折叠和表面作为其基本结构或其折叠核心的轻量系统。同时，该基本结构可以用于近似地确定自由成形的形状。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，因此可以用于建立新的轻质结构。参数研究与平板状结构的夹层结构，平面覆盖，折叠芯和一个恒定的折叠几何证明了他们的效率-高承载能力，在一个轻的自重。可以预期的是，这些质量特性可以通过使折叠结构的几何形状适应主要载荷情况的载荷来优化。虽然具有恒定折叠几何形状的折叠可以通过标准交联算法生成，但是面向载荷的折叠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，形成镶嵌和后续折叠的基础。在这个过程中，局部适应载荷的结果完全从几何参数的变化，如折叠频率和折叠的高度。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。所有的板和折叠元素都是基于由原始表面组成的网络，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。通过与原始几何形状的微小偏差和折叠元件的接触区域中的公差，可以组成类似的建筑元件的组。本研究旨在分析面向负载的薄板轻量化系统的基本原理和基本技术特征。计算机图形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。