A user-code computer program to obtain the performance point, effective damping and bilinear capacity curve representation of structures

Performance Level is served as an index defining the state of damage occurred in a building under specific ground motions, determining of which contains complex and iterative procedures that may not be straight-forward and accurate enough. This research aims to provide user-friendly and compatible tools in the form of a computer program in order to evaluate the performance level and seismic parameters of a structure, the capacity (pushover) curve data of which is obtained using any admissible method. The user-code is written in MATLAB programming and EXCEL spread-sheet environments. It is capable of determining the performance point of the structure using ATC-40 instructions, within a 0.5% tolerance. The exact bilinear representation of the capacity curve is also obtained, from which seismic parameters are extracted. The demand curves are automatically constructed by user-specified parameters according to the Iranian seismic code (Standard No.2800) for different seismic hazard levels and underlying soil types, as well as different ratios of structure’s effective damping.

Keywords:

Performance point , Effective damping , Bilinear representation , Pushover , Nonlinear static analysis