Numerical simulation of the three-sleeper asynchronous tamping operation of ballast bed based on the virtual unit module and polyhedral ballast model

Reasonable asynchronous tamping operation plays an important role in improving and maintaining the per-formance of the ballast bed. In studies conducted so far, constant velocity or angular velocity was applied to simulate the movement of tamping picks. This is in total contrast to the actual situation. For better simulation of three-sleeper asynchronous tamping operation, an innovative method of plane reconstruction and space fusion for rapid construction of polyhedral ballast particles was first proposed. The asynchronous squeezing of tamping picks was attained with the help of the coaxial rotation method for different bodies and a virtual unit module was developed. Then, a new relative velocity friction model was utilized to analyze the contact force inside the ballast bed. Finally, the coupling model of three-sleeper asynchronous tamping machine-ballasted track was established and verified. The results showed that the penetration stage has the greatest impact on the compactness of ballast at the bottom of the sleeper. The void ratio is relatively small, the elasticity and settlement of the ballast bed after tamping are minimum when the track lifting amount is 30 mm and the squeezing force is 7.8kN, and the tamping effect is the optimal.

Automated summary

Reasonable asynchronous tamping operation is crucial for the performance of the ballast bed. A novel method of plane reconstruction and space fusion for rapid construction of polyhedral ballast particles is proposed to better simulate the three-sleeper asynchronous tamping operation. The contact force inside the ballast bed is analyzed using a new relative velocity friction model. The results verify the effectiveness of the coupling model of the three-sleeper asynchronous tamping machine-ballasted track.