en Optimal design Optimal design پژوهشي Research Due to the favorable performance of structural topology optimization to create a proper understanding in the early stages of design, this issue is taken into consideration from the standpoint of research or industrial application in recent decades. Over the last three decades, several methods have been proposed for topology optimization. One of the methods that has been effectively used in structural topology optimization is level set method. Since in the level set method, the boundary of design domain is displayed implicitly, this method can easily modify the shape and topology of structure. Topological design with multiple constraints is of great importance in practical engineering design problems. Most recent topology optimization methods have used only the volume constraint<span dir="RTL">;</span> so in this paper, in addition to current volume constraint, the level set method combines with other constraints such as displacement and frequency. To demonstrate the effectiveness of the proposed level set approach, several examples are presented. topology optimization, level set method, multiple constraints, displacement constraint, frequency constraint 255 274 http://ijoce.iust.ac.ir/browse.php?a_code=A-10-66-184&slc_lang=en&sid=1 I. Manafi 180031947532846001300 180031947532846001300 No S. Shojaee 180031947532846001301 180031947532846001301 Yes