In this paper, a new computational model with appropriate specifications is presented for finite element analysis of local stresses at the intersections of longitudinal stiffeners with transverse frames under lateral loads in ship’s side structures. Because of the importance of such locations for fatigue analyses and also the dependence of these analyses on the maximum stress values at critical locations, performing the complete finite element analyses is to be a time consuming and expensive work for different details and locations. This is a special concern in the early stages of the design that the exact dimensions and scantlings of structural members have not been determined yet. In the proposed computational model, maximum stress concentration factors at structural details of intersections can be predicted by a simple finite element analysis. The results of this model is compared to that of the complete finite element analysis of a mid-side of a single side tanker, which have been done using ANSYS code, and it shows that the values of maximum stress concentration factors from simple model is about 10% to 15% greater than the complete analysis. This difference seems to be adopted as a proper safety factor in the early stages of design.