冷弯型钢构件抗火性能及设计方法研究

As a main material in steel structural buildings, cold-formed steel sections have many advantages, such as high section efficiency, good economy, easy industrilization, and green and envirenmental friendy, which lead a wide use in developed contries. Presently, cold-formed steel structures are developing quickly with good prospects in low-rise residentials, factories and office buildings, as weel as small tall buildings in China. However, research work on fire-resistant on cold-formed steel sections is really limited, and there are no related provisions in related design codes. This proposal will focus on investigation on fire-resistant bahviors of basic members and framing walls of cold-rolled steel sheets with thickness under 2mm, and basic members of cold-formed steel sections with thickness over 2mm, mainly including: 1)material properties of cold-formed steels with different processing, including cold-rolled sheets, heat-treated sheets, cold-formed sections and annealed cold-formed sections, under elevated temperatures; 2)fire-resistant behaviors of ultra thin-walled and thick cold-formed steel members; 3) fire-resistant behaviors and coresponding numerical simunation techniques of cold-formed steel framing walls as composite members; 4)fire-resistant design thoeries and methods for typical cold-formed steel members. The potential findings will offer the foundation to fire-resistant design theories of typical cold-formed steel members, and give some fundamental datas and theories for reversion of related design codes. Therefor, it is very important and necessary to resovle some key theoretical and technic problems for the use of cold-formed steels and prompting the use in steel structural buildings. Therefore, this project is important theoretically with practical value evidently.

冷弯型钢作为建筑钢结构主要用材之一，具有截面高效、经济性好和工业化程度高、绿色环保等特点，在发达国家应用广泛。近年来我国冷弯型钢行业发展迅猛，在低多层住宅、办公建筑和厂房以及小高层建筑领域呈现了广阔的应用前景，但有关冷弯型钢抗火方面的研究非常有限，相应设计技术标准还是空白。本项目拟针对2mm以下预涂渡超薄板基本构件（含龙骨式复合墙）及2mm以上冷弯型钢典型构件的抗火性能开展系统研究。主要内容包括：①冷弯型钢不同工艺（热处理板、冷轧板、冷弯板、退火板）钢材高温下力学性能；②冷弯型钢基本构件抗火性能；③冷弯超薄壁型钢龙骨式复合墙体抗火性能及数值模拟技术；④冷弯型钢典型构件抗火设计理论及方法。研究成果将为冷弯型钢结构典型构件抗火设计理论奠定基础，为相关标准的修订提供基础数据和理论依据，解决冷弯型钢用于建筑主构件时的制约性关键理论和技术问题，推进其在我国建筑钢结构领域的应用，具有重要意义。

冷弯型钢作为建筑钢结构主要用材之一，具有截面高效、经济性好和工业化程度高、绿色环保等特点。近年来我国冷弯型钢行业发展迅猛，在低多层住宅、办公建筑和厂房以及小高层建筑领域呈现了广阔的应用前景，但有关冷弯型钢抗火方面的研究非常有限，相应设计技术标准还是空白。本项目对2mm以下预涂渡超薄板基本构件及龙骨式复合墙体及2mm以上冷弯型钢典型构件的抗火性能开展系统研究。主要内容及成果包括：1）完成了冷弯薄壁型钢不同工艺（热处理板、冷轧板）钢材的50个高温材性试验，得到了其高温下力学性能的退化规律；2）完成了钢材高温材性不同试验方法的36个材性试验，基于数据比较得到了适用性比较结论；3）完成了冷弯薄壁型钢钢材高温后系189个材性试验，得到了其力学性能的退化规律；4）完成了冷弯厚壁型钢钢材考虑不同强化水平的56个高温材性试验，得到了其高温下力学性能基于不同强化水平的退化规律；5）结合墙体抗火试验，完成16根冷弯超薄壁及8根冷弯厚壁型钢基本构件高温承载性能试验，得到了高温下不同龙骨构件温度场分布及承载性能；开展了数值模拟分析，形成了冷弯型钢构件高温承载力计算有限元模拟技术；6）开展了4片冷弯型钢龙骨式复合墙体（包含冷弯薄壁型钢立柱及冷弯厚壁型钢立柱）抗火性能试验及其有限元模拟技术研究，得到墙体各组成部件的温度场分布及墙体的力学性能实测数据；7）基于系列试验及理论研究成果，提出了冷弯型钢典型构件抗火设计理论及方法。研究成果为冷弯型钢结构典型构件抗火设计理论和设计方法提供了基础，为相关标准的修订提供基础数据和理论依据，对解决冷弯型钢用于建筑主构件时的制约性关键理论和技术问题，推进其在我国建筑钢结构领域的应用，具有重要意义。