OPTIMIZATION OF THE SADDLE SUPPORT STRUCTURE OF THE FREIGHT WAGON TYPE SHIMMNS

Abstract

This paper presents the optimization process of the saddle support structure of the freight wagon type Shimmns intended for the transportation of the sheet coils using the Finite Element Method. Analysis of the information about the similar wagons and their behavior in exploitation, reveals that there are common characteristic critical areas where the initial cracks occurs, and those are the welded joints in saddle support structure. Due the existence of coil sheets with different dimensions, the whole range of coil sheets is modelled to cover all possible load cases in according to standards. Based on the results of the initial analysis, it is concluded that the greatest impact on the crack formation in the critical area has the fatigue of the material in welded zone caused by the cyclic fatigue loads in vertical direction. After the reason has been established, reconstruction was done in such a way that prevents the occurrence of the cracks on a new wagon. With reconstruction completed, new wagon with the modified support structure was analyzed in accordance with appropriate standards in the freight wagon industry for all of the load cases. Results with optimized support structure showed improvement, especially of stress reduction in critical areas.