ABSTRACT

Miniature buckling-restrained braces (MBRBs) have been widely used as energy dissipating dampers in precast concrete and steel beam-to-column connections for their superior seismic performance. This paper proposes a new type of all-steel MBRBs with corrugated core bars, termed as corrugated MBRBs (CMBRBs), of which the core bars are confined by circular hollow section restraining tubes. Several D-shaped cuttings, termed as D-cuts, are made on core bar to improve ductility, so that the CMBRB can have a shorter length compared with conventional MBRBs, which leads to smaller installation space of the beam-to-column connections. Six specimens were designed and tested under cyclic loading to investigate effects of slenderness ratio and segment spacing-to-D-cut cross-section height ratio on seismic performance, and it was found that the two parameters have great effects on strength, stiffness, energy dissipation capacity and ductility. A theoretical model was established to predict stiffness and strength of the proposed CMBRB. Finally, a design procedure and recommended values for the parameters were proposed.

摘要

微型屈曲约束支撑 (MBRB) 因其卓越的抗震性能而被广泛用作预制混凝土和钢梁柱连接中的消能阻尼器。本文提出了一种新型全钢波纹芯棒MBRBs，称为波纹MBRBs（CMBRBs），其芯棒由圆形空心截面约束管约束。为了提高延展性，在芯棒上制作了数个称为 D 形切口的 D 形切口，与传统的 MBRB 相比，CMRBB 的长度可以更短，从而导致梁柱连接的安装空间更小。设计了六个试件并在循环载荷下进行了试验，以研究长细比和管片间距与 D 型截面高度比对抗震性能的影响，发现这两个参数对强度、刚度、耗能能力和延展性都有很大的影响。建立了一个理论模型来预测所提议的 CMBRB 的刚度和强度。最后，提出了参数的设计程序和推荐值。