Design Method and Feasibility Study of Fully Actively Controlled Frames

In this paper, results of a preliminary study on the feasibility of using an Active Tendon Control (ATC) mechanism for frame structures subject to earthquakes is presented. So far, the ATC mechanism has mainly been considered as a means for installation on structures to mitigate their response under severe loading. In this study, it is desired to evaluate the possibility of using the ATC mechanism to serve as the main means for the stability of frames against earthquakes. Hence, a methodology is presented for the integrated design of frames with ATC mechanisms, which is tested numerically. A number of five-, ten-, fifteen- and twenty-story steel frames are used for this purpose. To this end, first, each of the frames is designed in accordance with the Uniform Building Code of Practice (UBC). Then, the same structure is re-designed for its dead load only, but equipped with a number of ATC mechanisms that help the structure withstand earthquake loading, so that its overall behavior is similar to the UBC frame. This results in a reduction of the cross-sectional dimensions and weight of the columns at the expense of providing the required hydraulic actuator(s), the sensory system, the controller chip(s) and the prestressed tendons. The ATC frame so designed is, then, considered to be equivalent or comparable to the UBC frame. Furthermore, the behavior of the ATC and UBC designs are compared.