Automatic calibration of hysteretic models through multiple responses

This paper describes MultiCal, a software package recently developed by the authors which is able to calibrate parameters of several hysteretic models implemented in OpenSees, by fitting experimental generalized strain-stress curves. The calibration is performed by means of a mul-ti-objective optimization procedure directly interfaced with OpenSees software, in which dis-crepancy between experimental and numerical responses is minimized. Up to six experimental responses may be utilized to increase robustness of the calibration, and for each one different quantities of interest can be fitted (raw data, energy, envelope). The applicability of the proce-dure is demonstrated by real-world examples involving steel components.