CTLGroup was contracted to conduct qualification tests on truck side frames for freight car applications in the North American market. Side frame were tested in accordance to the Association of American Railroads specifications (AAR) Manual of Standard and Recommended Standards (MSRP) M-203 “Truck Side Frames, Cast Steel – Design and Testing. “
The objectives of the tests were to evaluate the structural strength and durability of the truck side frames manufacturing quality and design. Castings were subjected to static loads and fatigue loads in accordance to the AAR standards. Typically, four side frames were subjected to fatigue loads and two were subjected to static loads.
Each side frame was subjected to three axes of synchronized 125,000 fatigue load cycles. The three axes consist of vertical, transverse, and twist loads. Side frames were periodically visually inspected for crack indications throughout the duration of the fatigue testing.
Side frames were subjected to transverse and vertical static tests. The static tests load cases represent overload scenarios to ensure castings do not have an excess of permanent deflection and that it can sustain an ultimate load.