EK形、Y形支撑的抗震性能试验研究

An Experimental Study on the Aseismic Properties for FK-Brace and Y-Brace in Steel Constructions

在多层及高层钢结构建筑中,多用X形和K形支撑。其缺点是在地震荷载作用下,当支撑杆件屈曲后,水平刚度及承载力都会下降,所以抗震性能差。本文以常用的K形支撑作为对比,取性能较好的EK形、Y形支撑形式,做成3榀单跨3层的大型试验模型,运用伪动力试验方法,分析了这3种支撑形式的结构在地震荷载作用下的时程曲线,恢复力特性,支撑局部的塑性变形对整个结构的影响及支撑部分的耗能效果。通过试验结果可以看出,由于EK形及Y形支撑的受剪板首先发生剪切屈服,有效地阻止了支撑杆件的屈曲,在整个试验过程中,承载能力没有降低。同时Y形支撑对框架横梁的变形影响最小,极限承载力也最高。

In multi-story or tall steel structures, X-brace and K- brace are often used asanti-seismic members. But the actual behaviour of these braces under the seismic loading isthat when buckling takes place, the horizontal stiffiness and the bearing capacity of thebracing members deerease rapidly. This paper reports on a comparative study of thecarthquake - resistant behaviour of the building with K-, EK- and Y- brace. Pscudo- dy-namic tests were carried out on three one -span, thrce - storcy frame models, each withone type of bracing, to investigate their history curves, restoring force characteristics,the effect of local plastic deformation on the scismic behaviour of the frames andcnergy -absorbing capacity of the braces. It can be seen that because the shear - plate yiel-ding occurs first in the EK - and Y -braced frames, which may prevent the buckling of thebracing members, the local- carrying capacity of the frames does not degenerate duringthe test. Y- brace has the least effect on the deformation of transverse beam and theY- braced frame has the highest load- carrying capacity.