مقاله انگلیسی رایگان در مورد مهاربند کمانش ناپذیر: تاریخچه، طراحی و کاربردها – Scientific 2018

Introduction

The buckling-restrained brace (BRB) is a seismic device consisting of an axially yielding core and axially decoupled restraining mechanism, which suppresses the overall buckling. The hysteretic characteristics are stable and nearly symmetric once the full cross section of the core has yielded, differing only slightly from the base material hysteresis. Because buckling is restrained, no associated degradation should be appeared during the compression cycles. For this unique behavior, BRBs can be modeled using truss elements and uniaxial material hysteresis rules, assuming strain is distributed along the full plastic core length.

The basic concepts of buckling-restrained braces appeared from the 1970s, when limited successes were reported by several researchers in Japan and India [1–3]. The first practical BRB was achieved by Saeki, Wada, et al. [4, 5] in 1988. They employed rectangular steel tubes with in-filled mortar for the restrainer, and determined the optimal debonding material specifications to obtain stable and symmetric hysteretic behavior. In addition, the basic theory to design the restrainer was established and the first project application soon followed. In 1989, these BRBs (unbonded braces) were applied to two 10- and 15-story steel frame office buildings, in the first project to use BRBs [6]. BRBs increased in popularity and other configurations soon followed, notably the all steel tube-in-tube type