MotivePower Incorporated (MPI) a Wabtec company and CTLGroup have completed stress testing of a new two-axle passenger locomotive truck (bogie) frame for use in North America. Testing was performed in accordance with International Union of Railways (UIC) Code 615-4 – Bogie Frame Structural Strength Tests [1]. Static testing was performed to simulate exceptional, main in-service and particular in-service loads. A three-phase dynamic fatigue test of 10 million cycles was also performed. Factors for quasi-static, dynamic and track twist (warp) loads were increased from those recommended by the UIC Code for normal operating conditions on European railways to represent North American track conditions. Significant engineering thought was invested in fixture design, with each load application and reaction point receiving careful consideration. Static testing required ten different servo-controlled loading systems to simulate independent or superimposed vertical, lateral and/or longitudinal forces. The applied loads represented tractive effort, braking effort, curving, vehicle lateral dynamics, vehicle vertical dynamics and track twist. Fatigue testing required four different servo-controlled loading systems utilizing synchronized force functions to simulate alternating quasi-static and dynamic load sequences. The apparatus also included provisions for measuring vertical reactions at each primary spring pocket. Vertical reaction loads were measured by instrumented pedestals using a full Wheatstone bridge configuration to cancel out longitudinal and lateral load effects. Prior to testing, the prototype truck frame was instrumented with 133 strain gages installed at selected points of interest. Stress values discerned from the measured strains conformed to the allowable stress criteria and compared well with those predicted by finite element analysis. Measured force reactions also showed strong correlation with predicted values. No indications of cracks were discovered during periodic non-destructive inspections. In conclusion, the UIC Code 615-4 test protocol was utilized to successfully demonstrate the strength and durability of a new two-axle passenger locomotive truck frame.

This content is only available via PDF.
You do not currently have access to this content.