装配式矩形钢管单层网壳的新型节点体系、稳定性能与设计方法研究

Adoption of RHS members in single-layer latticed shells leads to more reasonable mechanical behavior and aesthetic appearance, and thus has a great prospective of practical application. Rational and reliable prefabricated jointing system is a key point in the development and application of single-layer RHS latticed shells. With the principle of comprehensive performance requirements including mechanical behavior, geometrical adaptability, error tolerance, manufacture convenience and exterior appearance, new nodal joints suitable for prefabricated construction of RHS latticed shells will be developed by means of improvement of existing nodes and innovative design for new nodes. Through full-scale tests and numerical analysis with refined model accounting for material, geometrical and contact nonlinearities, semi-rigid behavior for the new prefabricated joints will be examined carefully, leading to mathematical models for moment-rotation relation and load-displacement relation and reasonable design method. Through large-scale model test and numerical analysis with refined model fully accounting for joint rigidity, elasto-plastic stability behavior of single-layer latticed shells with new prefabricated joints will be investigated thoroughly, leading to practical evaluation method for stability bearing capacity and applicability of new joints in free-form latticed shells. This project will provide solid theoretical basis and technical support for practical application of prefabricated single-layer RHS latticed shells, and also contribute to the development of jointing system for spatial structures and theoretical system for semi-rigid joints in spatial structures.

单层网壳结构中采用矩形钢管受力合理、外形美观，具有广泛的工程应用前景。合理可靠的装配式节点体系是矩形钢管单层网壳发展应用的关键。本项目以受力性能、几何适应、误差容忍、加工制作、外观效果等多方面的综合性能需求为原则，通过已有节点改良与创新节点设计，研发适应矩形钢管单层网壳装配化要求的新型节点体系；通过足尺节点试验及考虑材料、几何、接触非线性的精细化数值模拟，全面了解新型装配式节点的半刚性力学性能，建立强弱轴弯矩-转角、轴力-位移关系数学模型，形成科学设计方法；通过大比例结构模型试验及充分考虑节点刚度影响的精细化数值模拟，深入了解采用新型装配式节点单层网壳的弹塑性稳定性能，建立稳定承载力实用计算方法，验证新型节点对自由曲面网壳的适用性。本项目研究将为推动装配式矩形钢管单层网壳结构的工程应用提供坚实的理论基础和技术保障，并为丰富空间结构节点形式、完善空间结构半刚性节点理论体系作出贡献。

单层网壳结构中采用矩形钢管受力合理、外形美观，具有广泛的工程应用前景。合理可靠的装配式节点体系是矩形钢管单层网壳发展应用的关键。.本项目研发了一种适用于矩形钢管单层网壳的预埋螺栓装配式节点，具有无需杆件开孔、构造简单、传力路径清晰、装配简单等特点。通过理论推导、数值分析、模型试验等方法，较为系统地研究了新型节点的轴向、强轴抗弯、弱轴抗弯及抗扭力学性能，基于三参数幂函数模型，建立了节点的轴力-位移、强轴弯矩-转角关系拟合公式。提出了一种适用于矩形钢管单层网壳的双节点体系，并通过理论分析、有限元模拟和模型试验研究其力学性能和分析设计方法。建立新型装配式单层网壳稳定承载力计算分析方法，通过大规模参数分析研究采用新型装配式节点的矩形钢管单层网壳的弹塑性稳定性能，分析不同跨度、矢跨比、节点转动刚度、几何初始缺陷、荷载分布形式及杆件截面的网壳稳定承载力，建立稳定承载力实用计算方法，验证了新型节点对自由曲面网壳的适用性。.提出拓扑优化技术与增材制造技术相结合的空间结构节点设计方法，将连续体结构的拓扑优化引入自由曲面单层网壳、索杆张力结构的节点设计，得到受力性能合理、外形新颖美观的优化节点。对选择性激光熔融（Selective Laser Melting, SLM）、电弧增材制造（WAAM）两种技术制备的316L不锈钢制样进行拉伸试验，研究打印设备、试样方向和厚度对力学性能的影响，获得了弹性模量、屈服强度、抗拉强度、延伸率和泊松比等基本力学性能，为金属增材制造在结构工程中的应用奠定基础。.本项目研究为推动装配式矩形钢管单层网壳的工程应用提供了理论基础和技术保障，丰富了空间结构节点形式，完善了空间结构半刚性节点理论体系。