Unbonded posttensioning anchors a rocking structural member to its foundation and produces its controlled rocking response when the member undergoes seismic action. Unlike rocking of free‐standing bodies, little attention has been given to the dynamic behavior of these controlled rocking members. This paper utilizes experiments of concrete structural members with unbonded posttensioning, varying member geometries, and levels of initial posttensioning force to (a) characterize the associated impact energy loss and (b) improve modeling of controlled rocking motions. Experimental results show that impact energy loss in controlled rocking members can be captured accurately using the coefficient of restitution (r) approach of the modified simple rocking model (MSRM). Based on the MSRM, a controlled rocking model (CRM) is developed that additionally accounts for the variations in contact length at the member‐to‐foundation (rocking) interface. The CRM reproduces the experimental responses of controlled rocking members with good accuracy and is used to investigate controlled rocking motions under horizontal base excitations.

中文翻译：

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受控摇摆构件的动力响应和冲击能量损失

无粘结的后张紧力将摇摆的结构构件锚固到其基础上，并在构件受到地震作用时产生受控的摇摆响应。与独立式车身的摇摆不同，这些可控摇摆构件的动力学行为很少受到关注。本文利用具有无粘结后张力，变化的构件几何形状和初始后张力水平的混凝土结构构件进行试验，以（a）表征相关的冲击能量损失，以及（b）改善受控摇摆运动的建模。实验结果表明，利用恢复系数（r）修改的简单摇摆模型（MSRM）的方法。基于MSRM，开发了一种受控的摇摆模型（CRM），该模型另外考虑了成员到基础（摇摆）界面处接触长度的变化。CRM能够以较高的精度再现受控摇摆构件的实验响应，并用于研究水平基础激励下的受控摇摆运动。