Applied studies addressing semi-rigid connections have been limited. Scant information exists in regulations except little brief information. Therefore, this research analyzes the behavior of three-dimensional steel frames and semi-rigid connections based on beam-column method and non-linear dynamic analysis. Stability functions and geometric stiffness matrix were used to study the non-linear geometric behavior of members. Then the dynamic behavior of rotational springs was simulated by stiffening, and the non-linear load-displacement responses and the final results were compared to prior studies that have taken place. It was finally concluded that the method used to analyze the semi-rigid connections was efficient, and if one element per member is used and a precise monitoring is delivered, end sections and nonlinear steel frames behavior with semi-rigid connections can be predicted.
