考虑刚度折减的屈曲约束支撑整体稳定性设计方法

Overall stability design method of buckling restrained brace considering stiffness reduction

现有的屈曲约束支撑稳定性设计方法偏安全地忽略了内填混凝土和芯板的刚度贡献,导致对支撑整体稳定性的计算存在一定误差,不能准确地描述其屈曲机理。因此本研究将考虑内填混凝土和芯板的部分刚度,进行理论推导给出支撑整体稳定性的计算公式,并且拟合出了不同组合截面支撑中混凝土和芯板的刚度折减系数。然后,通过试验验证了文中所建立的有限元模型的可靠性,并进行了数值模拟,结果表明:本研究所拟合出的折减系数适用性更高,更接近支撑的实际工作状况;本研究提出的稳定性计算公式也能够准确地预测支撑的屈曲行为,并且适用于不同组合截面的支撑。因此,考虑混凝土和芯板刚度贡献的稳定性设计方法,能够更加准确地描述屈曲约束支撑的屈曲机理。

The existing buckling restrained brace stability design method neglects the stiffness contribution of the inner concrete and the core plate safely,which leads to some errors in the calculation of the overall stability of the brace and can not accurately describe its buckling mechanism.Therefore,this paper will consider the partial stiffness of concrete and core plate,theoretically deduce the calculation formula of the overall stability of the brace,and fit the stiffness reduction factor of concrete and core plate in different composite section braces.Then,the reliability of the finite element model established in this paper is verified by experiments,and numerical simulation is carried out.The results show that the reduction factor fitted in this paper is more applicable and closer to the actual working condition of the brace.The stability formula proposed in this paper can also accurately predict the buckling behavior of braces,and is suitable for braces with different composite sections.Therefore,the stability design method considering the stiffness contribution of concrete and core plate can describe the buckling mechanism of buckling restrained braces more accurately.