双矩管装配式防屈曲支撑约束刚度取值研究

STUDY ON RESTRAINING STIFFNESS OF DOUBLE RECTANGULAR TUBE ASSEMBLED BUCKLING-RESTRAINED BRACE

装配式防屈曲支撑的外围约束构件之间通过高强螺栓连接,其连系螺栓的离散性布置对各外围约束构件形成的整体约束刚度有不利的影响,需要在外围构件约束刚度计算中考虑。该文对一种双矩管装配式防屈曲支撑的外围约束刚度取值进行了研究,在理论推导中首先假定外围约束构件为"空腹桁架模型"来考虑离散螺栓连接,而后运用"连续连杆法"将螺栓的离散作用连续化以便于考虑这种不利作用。通过研究"空腹桁架模型"的变形特性考虑外围约束构件约束刚度的折减,最后结合对外围构件受力机理的分析及数值手段,推导并拟合出约束构件分肢间连系刚度,进而完善了外围约束刚度取值的相关理论。提出的方法也得到了数值分析的验证。

The external restraining members of an assembled buckling-restrained brace are held together by high-strength bolts, which should be considered in the calculation of external member restraining stiffness, as the discrete layout of the connection bolts has adverse impact on the integral restraining stiffness of the external restraining members. This study puts forward the calculating method for external restraining stiffness of double rectangular tube assembled BRB. In the theoretical derivation, the external member is assumed as a vierendeel truss to consider the discrete bolt connection and then the 'continuous link method' is applied to consider the bolt connection continuously, so as to quantify the adverse effect due to discrete bolts. By investigating the deformation character of the vierendeel truss, the stiffness reduction of the external restraining member is obtained, and the link stiffness between external members is finally reached by analyzing the mechanical mechanism of external members and by fitting numerical results, thus the stiffness calculation theory of external restraining members is refined. The research results are verified by the numerical analysis.