中心支撑-框架钢结构设计与研究

对人字形中心支撑-框架结构的抗震设计进行研究。在不同的支撑长细比下,支撑受压屈曲后的强度退化程度是不同的。根据我国抗震规范规定的设计支撑强度的方法,当取不同的长细比λ时,会产生不同的结构初始刚度和变幅很大的强度值,且工程设计很复杂。为此,提出一新的支撑强度设计方法,并认为人字形中心支撑的强度是由一侧杆受压后屈曲强度与另一侧杆的受拉屈服强度两部分构成。新的设计方法确保了结构初始刚度和强度不受支撑长细比影响。建议方法的优点还在于其能够较好地控制最大层间位移角。最后,深入探讨了多层钢支撑-框架结构出现薄弱层的问题。

STUDY AND NEW DESIGN METHOD FOR CHEVRON-BRACED STEEL FRAMES

It is studied the seismic design of steel braced frames in which the braces are configured in a chevron pattern.Strength deterioration in post-buckling phase varies with the slenderness ratio of brace.Because the present chinese seismic code method for the calculation of brace strength supplies significantly different elastic stiffness and actual strength for different values of slenderness ratio of brace,it is complicated for the design of chevron brace.A new procedure to estimate the strength of a chevron brace is proposed,in which the strength of a brace pair is the sum of the yield strength for the brace in tension and the post-buckling strength for the brace in compression.The new method ensures an identical elastic stiffness and a similar strength regardless of the slenderness ratio of brace.The advantage of the proposed method over the conventional chinese seismic code method is demonstrate for the capacity of the proposed method to control the maximum inter-story drift.Finally,concentration of multi-story chevron-braced frames is discussed.