抗拔型三维隔震支座力学性能研究

Research on mechanical characteristics of anti-extraction three-dimensional seismic isolation bearing

为解决传统隔震支座竖向抗拔能力较差,且不能对建筑结构进行竖向隔震等问题,提出一种具有较优抗拔能力的三维隔震支座,并研究了该支座水平及竖向自由度的力学性能。首先将具有竖向隔震能力的碟簧组装置与高阻尼橡胶隔震支座串联结合,然后在支座外部设计抗拔装置,共同组成抗拔型三维隔震支座。而后建立了三维隔震支座实用分析模型,并对其水平和竖向力学性能进行计算,通过与试验结果进行对比,以验证模型的有效性;之后对三维隔震支座转动自由度及承受上拔力时的力学性能进行了数值分析。研究结果表明:三维隔震支座实用模型能有效模拟三个平动自由度的力学性能。当支座处于隔震状态时,抗拔装置还起到传导高阻尼橡胶隔震支座提供的水平力作用。得到了转动自由度的刚度曲线及弯矩-转角曲线,其中弯矩-转角曲线近似为双线性模型;支座抗拔能力较强,在抗拔装置发挥作用之前,荷载-位移曲线会出现零刚度段;得到了抗拔装置发挥作用时的三维隔震支座的荷载-位移曲线,为隔震结构出现上拔力时的动力计算提供条件。

In order to solve the disadvantages of the traditional seismic isolation bearing such as poor of the vertical anti-extraction resistance and can not be used for vertical isolation of building structures, a three-dimensional seismic isolation bearing with better anti-extraction resistance was proposed, and and the mechanical characteristics of the horizontal and vertical degrees of freedom of the seismic isolation bearing were also studied. First, the disc spring assembly device with vertical seismic isolation capability was connected in series with the high damping rubber seismic isolation bearing, then the anti-extraction device was designed outside the support to form an anti-extraction three-dimensional seismic isolation bearing. Secondly, a practical analysis model of the anti-extraction three-dimensional seismic isolation bearing was established, and its horizontal and vertical mechanical characteristics were calculated, which were compared with the test results to verify the effectiveness of the model;after that, numerical analysis was carried out on the degree of rotation freedom of three-dimensional seismic isolation bearing and the mechanical performance when it bears the pull-up force. The study results show that the three-dimensional seismic isolation bearing practical model can effectively simulate the mechanical characteristics of three translational degrees of freedom. When the bearing is in isolation state, the anti-extraction device also plays the role of conducting the horizontal force provided by the high damping rubber seismic isolation bearing. The stiffness curve and the moment angle curve of the rotational freedom were obtained, and the moment-angle curve is approximate to bilinear model;the bearing has strong anti-extraction resistance, before the anti-extraction device works, the load-displacement curve will appear zero stiffness section;the load-displacement curve of the three-dimensional seismic isolation bearing when the anti-extraction device works was obtained, which provides conditions for the dynamic calculation of the isolated structure when the pull-up force occurs.