en Optimal design Optimal design پژوهشي Research <span style="font-size:11.5pt"><span new="" roman="" style="font-family:" times="">The main purpose of this paper was to use a combination of Energy-based design method and whale algorithm (WOA), hereinafter referred to as E-WOA, to optimize steel moment frames and improve the seismic performance. In E-WOA, by properly estimating the seismic input energy and determining the optimal mechanism for the structure, steel frames are designed based on the energy balance method; according to the results, in a suitable search space, optimization is performed using the WOA algorithm. The objective function of the WOA algorithm, in addition to the frame weight, is meant to improve the behavior of the structure based on the performance level criteria of the ASCE41-17 standard and the uniformity of the drift distribution at the frame height. The results show that the initial design of the Energy method reduces the computational volume of the WOA algorithm to achieve the optimal solution and the plastic hinge pattern in frame is more favorable in the E-WOA method than in the design done by the Energy method.</span></span><br> &nbsp; energy-based design methods, whale algorithm, optimization of steel moment frame, lateral loading pattern, nonlinear static analysis. 365 398 http://ijoce.iust.ac.ir/browse.php?a_code=A-10-66-346&slc_lang=en&sid=1 R. Bagherzadeh 180031947532846002689 180031947532846002689 No Department of Civil Engineering, West Tehran Branch, Islamic Azad University, Tehran, Iran A. Riahi Nouri 180031947532846002690 180031947532846002690 No Department of Civil Engineering, West Tehran Branch, Islamic Azad University, Tehran, Iran M. S. Massoudi masoudi.ms@wtiau.ac.ir 180031947532846002691 180031947532846002691 Yes Department of Civil Engineering, West Tehran Branch, Islamic Azad University, Tehran, Iran M. Ghazi 180031947532846002692 180031947532846002692 No Department of Civil Engineering, West Tehran Branch, Islamic Azad University, Tehran, Iran F. Haddad Sharg 180031947532846002693 180031947532846002693 No Department of Civil Engineering, West Tehran Branch, Islamic Azad University, Tehran, Iran