【摘要】 防屈曲支撑通常采用刚接节点与框架结构相连,而内核构件端部构造形式复杂,常出现外伸屈服段与加强段等,端部构造形式复杂,由此形成的复杂边界约束条件将对防屈曲支撑的整体性能产生显著影响。通过理论推导与有限元分析,对两端刚接边界条件下端部构造形式对防屈曲支撑整体受力性能的影响进行了研究。研究表明:相比于铰接边界条件,刚接边界条件能有效防止外伸段发生过大的侧向变形,两端刚接防屈曲支撑比两端铰接防屈曲支撑表现出更好的受力性能,即使在实际框架结构中防屈曲支撑两端出现转角时亦然。基于理论推导与有限元分析,提出了内核构件端部段的简化计算模型,采用迭代算法,可用于近似确定内核构件端部外伸段转角及变形在外围约束构件两端产生的不利附加偏心距;框架结构中防屈曲支撑两端转角不同,可用等效附加偏心距系数将两端不等附加偏心距的情况等效为两端等附加偏心距的情况;考虑等效附加偏心距的影响,给出了适用于两端刚接防屈曲支撑的整体设计方法。更多还原

【Abstract】 The buckling-restrained braces(BRBs) are often connected to the frame structures by fixed joints in practice,and the cores usually have complicated details near the ends,namely unsupported yielding segments and/or strengthened segments.Based on theoretical and numerical analysis,this paper presents the influence of complicated boundary constraints on the behaviors of the BRBs.It is revealed that the fixed joints can effectively prevent the core unsupported segments from bending too much,and BRBs with fixed ends usually perform better than those with pinned joints,and the advantage exists even when the ends of BRBs rotate with frame joints in the structures.Based on theoretical and FEA results,a simplified model is proposed to simulate the core segments near the BRB’s ends.Using an iterative algorithm cooperatively,the simplified model can approximately determine the unfavorable additional eccentricities at the ends of restraining part.In the frame structures the rotations at two ends of the BRB are unequal,and the two different eccentricities can be equivalent to the same eccentricity by equivalent eccentricity coefficient.Finally,by taking the equivalent additive eccentricities obtained into account,a design procedure for the fixed-fixed BRBs is achieved.更多还原