六杆四面体单元组成的新型可装配球面网壳的理论与试验研究

Lattice shell is one of the most widely used space structures for its high adaptive capacity and efficiency, as well as its excellent mechanical properties. The advantages of the lattice shell in industrialized production and construction make it comply with the trend of building industrialization in China. This project proposes a novel lattice shell composed of six-bar tetrahedron units whose planar projections are quadrilateral. The new lattice shell has a simple configuration with attractive appearance, and shows a mixture of the characteristics of both single-layer and double-layer lattice shells. The standardized design, industrialized production and fabricated construction for this lattice shell can be easily implemented. Study on the configuration, static and dynamic properties, stability behavior and failure mechanism of the lattice shell will be conducted through systematical theoretical analysis and large-scale model test. A new joint system which satisfies the requirements of fabricated construction will be developed and a practical design method for the joint will be established by carrying out numerical analyses and full-scale experiments. A set of industrialized construction system, which aims at balancing the quality and the efficiency during the building process, will then be fully developed. This project will provide China's building industrialization with a reliable space grid structural system by making a solid theoretical and practical preparation for its engineering application, and the work involved will stimulate the research and development of other industrialized building systems.

网壳结构是工程应用最广的空间结构形式之一，具有良好的适应能力和优越的技术经济指标，且在工业化生产、建造方面具有优势，契合我国当前新型建筑工业化的发展趋势。本项目提出一种新型球面网壳结构，该网壳由平面投影为四边形的六杆四面体单元组合而成，构成简单、造型美观、兼具单双层网壳结构特点，便于标准化设计、工厂化生产和装配化施工。项目将通过系统的理论分析和大比例模型试验研究，全面了解新型球面网壳的构形、静动力性能及稳定性能，揭示其破坏机理；研发适用于装配化要求的新型节点体系，通过深入分析和足尺试验全面了解新型节点的受力特点，提出实用设计方法；提出一套完整的工厂预制生产、现场装配施工的施工技术体系，形成质量和效益兼顾的建造方案。本项目的研究将为六杆四面体单元新型球面网壳的工程应用做好理论和实践方面的准备，为我国建筑工业化提供一套成熟的空间网格结构新体系，并为其他工业化建筑体系的研发提供经验和参考。

本项目首先提出了多种由六杆四面体单元构成的不同曲面形式的网壳，包括球面网壳、柱面网壳、扭网壳和双曲面网壳，并对其进行了构形分析。六杆四面体组成的网壳构造简单，施工方便，易于实现工业化生产和装配化施工。利用结构力学知识和矩阵的基本理论进行了机动性分析，总结了网壳杆系结构静定的必要条件，在此基础上探讨了网壳刚性节点的布置方式和结构体系的实用加强方式；使用通用有限元软件对各种曲面形式的网壳进行建模，分析了其在基本荷载作用下的静力与稳定性能，结果表明其受力性能良好、经济指标优越；对一种典型的六杆四面体网壳节点进行建模，完成了受力性能和参数敏感度分析，并提出了平面外刚度的拟合公式；制作了多种不同曲面形式的六杆四面体网壳整体结构模型和节点模型，基于该模型进行了装配化施工的实践研究和静力特性模型试验，模型试验结果与有限元分析相吻合。