Performance of rocking frames with friction tension-only devices

The implementation of a new friction tension-only “GripNGrab” device attached to rocking steel frame is described. device, when subject significant tension dissipates energy via sliding in the frictional component. When loaded compression direction, almost no compressive force carried, but displacement occurs ratchetting This absence any within dissipative system means that will always recentre after uplift from earthquake shaking. A 9 m tall 4.75m wide 3-storey concentrically braced designed for low-damage seismic performance. Restoring forces are provided by (i) gravity, (ii) (GNG) dissipation devices at base, and (iii) beam-slab effects. initial fundamental period structure was 0.16s. used 10mm GNG ratchet pitch, had strength not slide under serviceability level Elastic, pushover, cyclic as well time history analyses, with different shaking intensities conducted using OpenSEES software. scope work limited single building ground motion. Parameters varied included presence effects, stiffness, tooth pitch. It shown full behaviour could be understood considering pushover analysis. peak conservatively estimated roof rigid body mechanics resistance recentring. For frames considered, cumulative displacements, necessary determine inelastic capacity only were up 28 times displacement, necessarily occurring maximum intensity. Maximum base shear demands 1.43 beam-slab, connecting rest structure, increased lateral resistance, significantly, reduced effective number cycles (NPUDc). large intensities, yielding occurred resulting permanent displacements. strength, stiffness pitch variations cases studied did significantly affect response. Initial secant based methods predict response non-conservative these short-period structures small dissipation, simple improvement match developed case on R-T-m relationship range