Matching Relationship Between Axle Load And Speed Of Heavy-Haul Freight Truck Based On Running Safety Performance

With more than ten years of innovation and development, China’s railway freight capacity increases rapidly.25%of the world railway traffic volume has been completed by using only6%of the world’s rail mileage in China’s railway. It indicates that the heavy-haul transportation technology in China has reached the world’s advanced level. But the main axle loads of heavy-haul wagon truck are still no more than25t in China’s railway. There is a large gap between our country and other heavy-haul transportation developed countries. Now our country is developing heavy-haul wagon trucks with the axle loads of25t or larger. With the increase of axle-load and train speed, the wheel/rail forces increase accordingly, and also the track structure and the components of track are damaged seriously. Therefore, this paper dedicates to the study of matching relationship research between the axle load and the speed for the wagon truck with the axle load of25t,27t and30t. It can provide some theoretical references for the engineering of carrying out large axle load wagon trucks in our country.By means of the dynamics analysis software SIMPACK, dynamic models of the heavy-haul wagon truck are established, with taking various nonlinear factors into account. Dynamics simulation analyses of different axle load wagon trucks running on various lines are carried out.Research results show that, dynamic performances of the loaded and unloaded wagon truck are different obviously. The wheel/rail forces of the unloaded wagon truck are much smaller than the loaded wagon truck, while the running safety of the unloaded truck is poorer than the loaded wagon truck. The wheel/rail forces increase with the increasing of the speed and the axle load on tangent track. When the truck passes through the curved track, the wheel/rail forces decrease firstly and increase later with the increasing of the speed.When the wagon trucks with the axle load of25t,27t and30t running on the tangent track at the speed of90km/h, the running safety can meet the requirements. As for the curved track with a radius of600m, the wheelset decreasing ratio of both25tand27taxle load wagon trucks exceed the standrad. As for the curved track with a radius of800m, the wheelset decreasing ratio of the25t axle load wagon truck with the speed of100km/h is out of limit. As for the curved track with a radius of1000m, the wheelset decreasing ratios of25t,27t and30t axle load wagon trucks are all meet the requirements.For the unloaded wagon trucks, when the truck with the axle load of25t running on the tangent track at the speed of70km/h, the wheelset decreasing ratio is over the limit. And the wheelset decreasing ratios of the trucks with axle loads of27t and30t exceed the standard at the speed of80km/h. As for the curved track with a radius of600m, the wheelset decreasing ratios of25t,27t and30t axle load wagon trucks are all beyond the standard at the speed of70km/h. As for the curved track with a radius of800m, the wheelset decreasing ratios of25t and27t axle load wagon trucks exceed the limit at the speed of70km/h, while the wheelset decreasing ratio of the30t axle load wagon truck exceed the standard at the speed of80km/h. As for the curved track with a radius of1000m, the wheelset decreasing ratio of the25t axle load wagon truck is beyond the standard at the speed of70km/h, while the wheelset decreasing ratios of27t and30t axle load trucks exceed the standard at the speed of80km/h.