杜雷++陈忠++周茗如++张太亮

摘要：设计了12个无约束段的防屈曲支撑构件，利用ABAQUS软件对其进行有限元分析，研究无约束段长度、是否利用槽钢加强无约束段及加强槽钢的长度和厚度对构件滞回耗能性能及承载力的影响。结果表明：无约束段长度对防屈曲支撑构件滞回耗能性能及承载力影响显著，当无约束段长度与构件在轴力作用下产生的最大位移近似相等时，构件耗能效果更明显；经槽钢加强的构件具有良好的滞回耗能性能及承载力；无约束段加强槽钢的长度对构件滞回耗能性能与承载力影响显著，加强槽钢的长度为无约束段长度的2倍时，构件具有更好的滞回耗能性能与承载力；加强槽钢的厚度对构件的滞回耗能性能与承载力影响不大，设计构件时可适当减小槽钢的厚度以提高材料的利用率。

关键词：防屈曲支撑；无约束段；槽钢加强；有限元分析；滞回耗能性能

中图分类号：TU391文献标志码：A

Influence of Unconstrained Segments on Hysteretic Energy Dissipation

Performance of Bucklingrestrained Braces with Hsection CoreDU Lei1，2， CHEN Zhong1， ZHOU Mingru1， ZHANG Tailiang2

（1. School of Civil Engineering， Lanzhou University of Technology， Lanzhou 730050， Gansu， China；

2. Gansu Science Research Institute of Civil Engineering， Lanzhou 730020， Gansu， China）Abstract： 12 different bucklingrestrained braces with unconstrained segments were designed， and finite element analysis was carried by ABAQUS software to study the influences of unconstrained length， whether the channel strengthened unconstrained segment or not， and the channel with different lengths and thicknesses on the hysteretic energy dissipation and bearing capacity of components. The results show that the length of the unconstrained segment has a significant influence on the hysteretic energy dissipation performance and bearing capacity. The influence of energy dissipation is more obvious when the length of unconstrained segment is equal to the maximum displacement of component under axial force. The components strengthened by channels have good hysteretic performance and bearing capacity. The length of unconstrained segment strengthened by the channel has obvious influence on the hysteretic energy dissipation performance and bearing capacity. When the channel length is 2 times than unconstrained segment length， the components have better energy dissipation and bearing capacity. Strengthening channel thickness has little effect on the hysteretic behavior and bearing capacity of components， so the thickness of the channel can be reduced in design to improve the utilization rate of materials.

Key words： bucklingrestrained brace； unconstrained section； channel strengthening； finite element analysis； hysteretic energy performance

0引言

防屈曲支撑（Bucklingrestrained Braces，BRB）是一种无论受拉还是受压都能够使内芯达到屈服而未屈曲的耗能支撑构件[15]，其主要是由内芯构件与外围约束单元组成。通常内芯构件承受轴力作用，外围约束单元抑制内芯构件在受压时发生屈曲，提供侧向支撑[610]。由于普通支撑在受压时很容易发生屈曲破坏，不能充分利用钢材的延性，滞回性能较差；相比普通支撐，防屈曲支撑充分利用材料的延性发生屈服而不屈曲，其滞回性能良好[1114]。

各国对防屈曲支撑已有较多的研究，Gennaa等[15]分析了轴向力和内核单元多模态屈曲变形波长的关系以及影响内芯以不连续方式产生侧向推力的几个因素；……