Load Identification and Deflection Monitoring of Opening Beam on Well-Hole Freight Trains

In railway freight transport of over-size cargos, elastic deflection of overloaded structures is the main cause of train-line collision in running. Deflection monitoring remains a challenge for the non-uniform and opening beam on well-hole freight cars. This work presented a new approach by strain perception and Finite Element Analysis (FEA). In theoretical modeling, support locations and the geometry symmetry were taken into account, to identify the support loads with bottom strains in single loading. Deflection calculation was developed by mathematically correlating bottom deflections with support loads, and further extended to the concerning region of the non-uniform and opening beam. Validation underwent in loading simulation and tests. The identified deflection deviates from the read and measured within 5.98%. In application, in-transit monitoring reveals that the most unfavorable vertical cargo movement, which is calculated with the identified support deflections and the measured suspension displacement, climbs up to 231.6 mm in synthetic evaluation, when the train runs on a 400-m radius line curve at the speed of 19.6 km/h. The detecting maximum is within but very close to the limit dimension between cargo bottom and rail top, 250 mm. Hence, it is recommended to measure the limit after the transformer is loaded. Research outcome indicates that the proposed approach enables the real-time deflection monitoring and safety evaluation in railway freight transport, which offers scientific evidence for its operation maintenance and structural optimization.