Abstract Summary
Recently, a novel Sliding Keys on Inclined Deflecting-cantilever (SKID) device was proposed for application with Post-Tensioned (PT) frames. The SKID device has a triangular-shaped hysteretic curve; thus, it can provide hysteretic damping without an activation threshold in the PT frame. The properties of the device have been theoretically investigated and physically demonstrated. In this paper, the force-deformation relationship of the PT frame with the SKID device (the PT-SKID frame) is theoretically derived. The PT-SKID frame has a triangular flag-shaped hysteretic curve with full self-centring capability. A numerical model of a one-storey one-bay PT-SKID frame is built in OpenSees and benchmarked by the analytical equations. The model is used to investigate the dynamic characteristics of the PT-SKID frames by generating frequency response functions (FRFs) from sin-sweep excitations. More than 700 PT frame configurations with different SKID devices are numerically tested. The influence of SKID parameters on the seismic response of PT-SKID frames is highlighted. The results indicate that: (1) the PT-SKID frames show the same typical dynamic characteristics of nonlinear systems: their FRFs include two amplitude branches enveloping a coexisting solution region, but the SKID device considerably reduces the range of coexisting solutions; (2) the SKID device with larger loading stiffness and friction coefficient, and a smaller slope angle leads to a smaller seismic response amplitude.
