Seismic Behaviour of Structures
Abstract
In the seismic design spectra in the Loadings Standard no recognition is given for the influence of differing hysteretic behaviour associated with different materials, structural types and detailing standards. In practice hysteretic behaviour varies widely, from the near bilinear typical of eccentrically braced frames to the pinched forms associated with masonry.
To investigate this a series of time history analyses were made with different ground motions and a range of hysteretic models. It is shown that the hysteretic form, provided that appreciable energy can be dissipated, has only a small influence on the maximum displacement that is sustained. Varying the viscous damping level was found to have a significant influence on elastically responding structures but a smaller effect on structures with some ductile capacity. Increasing the strain-hardening ratio was found to have a small influence on the required strength for a given ductility.