往复荷载作用下自复位墙滞回性能研究

Study on hysteretic performance of self-centering wall subjected to cyclic loading

将自复位墙简化成刚体,研究了往复荷载作用下自复位墙的滞回性能。通过理论推导,得出往复荷载作用下自复位墙的水平力-转角滞回曲线,给出了各特征点水平力和转角及等效黏滞阻尼系数的表达式,推导了自复位墙保证自复位性能应满足的条件,并提出了自复位墙简化滞回模型。在此基础上,通过参数分析进一步研究了预应力筋及阻尼器设计参数对自复位墙滞回性能的影响。结果表明:自复位墙的转动临界荷载与墙体自重及预应力筋的初始力有关;墙体完全卸载时是否有残余变形与墙体自重、预应力筋初始力及阻尼器屈服力有关;阻尼器屈服力对自复位墙滞回性能影响最大,预应力筋初始力及弹性刚度影响相对较小,阻尼器弹性刚度及布置位置影响最小。

The self-centering wall was simplified as a rigid body and its hysteretic performance under cyclic loading was studied. By way of theoretical derivation, the horizontal load vs. rotation curve of the self-centering wall subjected to cyclic loading was obtained along with the analytical expressions of the horizontal load and rotation pertaining to the prescribed characteristic points and the equivalent viscous damping ratio. The condition which should be met to ensure self-centering behavior for the self-centering wall was also given. In addition, the simplified hysteresis model of self- centering wall was proposed. Based on the above work, the effect of design parameters concerning the prestressing tendons and dampers on the hysteretic performance of self-centering wall was investigated through parametric analyses. It is indicated that the critical load leading to the rotation of the self-centering wall is related to the self-weight of the wall and the initial force of prestressing tendons. Whether the self-centering wall is unloaded with or without residual deformation depends on the self-weight of the wail, the initial force of prestressing tendons and the yield strength of the dampers. The yield strength of dampers has the largest impact on the hysteretic performance of self-centering wall, while the effect of initial force and elastic stiffness of prestressing tendons is relatively small and that of the elastic stiffness and location of dampers is minimal.