测定钢货架竖版的横向抗剪刚度

通过螺栓连接的冷弯薄壁型钢竖直框架确保钢货架在多横向走道方向的稳定性。对二阶效应很敏感并能精确测定框架的抗剪刚度是抗震设计中必不可少的;由于外部的钢框架必须能够承受在多横向走道上风力所带来的水平位移,这也是确保货架整体稳定性,特别是高钢架和钢架支承建筑围护结构中至关重要的。钢架制造协会使用了Timosh-enko理论和Gere理论来进行保守的计算并推荐欧洲标准EN15512对其进行测试,然而并不能确定根据所推荐的测试程序得到的抗剪刚度是否正确。介绍的新修正后的澳大利亚标准AS4084适用于欧盟,同时也介绍了另一种测定直立框架横向弯矩和抗剪刚度共同作用的测试方法。文章评论并分析了影响冷弯薄壁型钢的螺栓竖直框架的剪力变形,介绍了一种在澳大利亚标准修正版中采用的检测装置。使用两种不同的测试方法对36个竖直框架进行测试,对试验结果进行讨论并与有限元分析得出的结果相比较。同时对在设计中如何运用这些测试结果提出了一些建议。基于这些建议,文章中认为这两种测试方法是不等效的,并且竖直框架的横向抗剪刚度的结果是不同的。

Determining the Transverse Shear Stiffness of Steel Storage Rack Upright Frames

The stability of steel storage racks in the cross-aisle direction is typically ensured by cold-formed steel bolted upright frames. Sensitive to second-order effects, accurately determining the shear stiffness of these frames is essential for seismic design and for ensuring the stability of the rack, especially for high-bay racks and racks supporting the building enclosure, where the outer rack frames must withstand cross-aisle horizontal actions due to wind loading. The main international racking specifications adopt different approaches to determining the shear stiffness of cold-formed steel storage rack upright frames. The Rack Manufacturers Institute (RMI) specification conservatively uses Timoshenko and Gere's theory. The European Specification EN 15512 recommends testing, however it is not clear whether the shear stiffness obtained using the recommended test procedure is correct. The newly revised Australian Standard AS 4084 adopted the European approach but also introduced an alternative test method for determining the combined bending and shear stiffness of upright frames in the transverse direction. This paper reviews and analyses the factors influencing the shear deformation of cold-formed steel bolted upright frames and introduces the alternative test set-up adopted in the revised Australian Standard. 36 upright frames have been tested using the two test methods, and experimental results are presented, discussed and compared with finite element analysis results. Recommendations on how to use the test outcomes in design are also provided. Based on these recommendations, the paper shows that the two test methods are not equivalent and yield different results for the transverse shear stiffness of upright frames.