Qualitative review of seismic response of vertically irregular building frames
This study summarizes state-of-the-art knowledge in the seismic response of vertically irregular building frames. Criteria defining vertical irregularity as per the current building codes have been discussed. A review of studies on the seismic behavior of vertically irregular structures along with their findings has been presented. It is observed that building codes provide criteria to classify the vertically irregular structures and suggest dynamic analysis to arrive at design lateral forces. Most of the studies agree on the increase in drift demand in the tower portion of set-back structures and on the increase in seismic demand for buildings with discontinuous distributions in mass, stiffness, and strength. The largest seismic demand is found for the combined-stiffness-and-strength irregularity.
This chapter first examines how to model the impact-contact between a rigid projectile and the surface of an elastic-plastic structure and how this local behaviour interacts with the global deformation of the structure. Then, a particular type of energy-absorbing structure, namely type II, is analysed in order to explore why the deformation of such structures is sensitive to the impact velocity, or to the inertia of both the striker and the structure itself.