抑制屈曲支撑滞回性能分析

为研究采用我国Q235B钢和两种无黏结材料设计制作的抑制屈曲支撑试件的滞回性能，对6个试件进行了拉压循环荷载作用下的滞回性能试验．其中，利用钢管混凝土抗弯承裁力理论和连续弹性约束体的稳定理论完成支撑整体稳定与内核构件约束段高模态稳定设计；外伸无约束段钢板宽厚比满足我国铜结构规范塑性设计的要求；选取适当厚度的无黏结材料以控制内核构件与外包铜管混凝土之间间隙的大小，最后基于ANSYS对试件的滞回性能进行了有限元分析．在试验过程中抑制屈曲支撑试件没有发生稳定破坏，拉压屈服后均有明显应变强化，最大延性接近设计值15，累计延性超过700．滞回曲线稳定饱满，耗能能力强，拉压承载力差值控制在10％左右，恢复力模型可简化为对称双线性模型．内核构件采用一字形比采用十字形截面的试件滞回性能更好．有限元分析结果与试验结果吻合良好．因此设计制作的抑制屈曲支撑所采用的材料、构造措施及设计方法均较为合理，能保证其具有优良的滞回性能．

Analysis of Hysteretic Behavior of Buckling-Restrained Brace

In order to research the hysteretic behavior of six buckling-restrained braces （ BRBs ） which were fabricated with Chinese Q235B steel and two types of unbonded materials, experimental research on the hysteretic behavior of BRBs under cyclic load were completed. The integral flexural buckling of entire BRBs and the buckling of inner core in higher modes were designed with the theory of ultimate flexural strength of concrete filled steel tube （ CSFT ） and the stability theory of continuous elastic confined member. The width thickness ratio of the segment of inner core that extended beyond CSFT was satisfied to meet the demand of plastic design in the Chinese code for design of steel structures. The proper unbonded materials of appropriate thickness were chosen to form the adaptive interspaces between inner core and CSFT. At last the finite element analysis based on ANSYS were carried out. In the process of experiment, BRBs did not buckle. And they could develop obvious strain intensification after tension and compression yielding, with ultimate ductility close to 15 and cumulative plastic ductility beyond 700. BRBs could undergo fully-reversed axial yield cycles without loss of stiffness and strength, and the energy absorption was good. The difference of ultimate compression and tension strength was about 10%. So the resilience model can be simplified to a symmetrical bilinear resilience model. The hysteretic performance of BRBs with rectangle section was better than BRBs with cruciform section. The results of finite element analysis based on ANSYS agree well with the experimental results, indicating that the materials, conformation and the design method used to design and manufacture BRBs are reasonable, so the hysteretic behavior of the BRBs is good.