A study on the fracture of primary steel springs for metro vehicles
In response to the frequent occurrence of primary steel spring fractures in the bogies of Kunming metro vehicles,macroscopic and microscopic inspections were conducted on the fracture surface of those primary steel springs.Furthermore,the hardness of the steel springs was also measured.Meanwhile,wheelset radial run-out measurements and out-of-roundness testing were carried out.To further elucidate the relationship between the stresses of primary steel springs,vibration sensors and strain gauges were installed on the primary steel springs,and vibration tests were conducted on the main line.Based on the acquired test data,strength verification tests were carried out.The results showed that the dynamic stress of the primary steel springs before wheelset lathing could not satisfy the fatigue strength requirements.In addition,the dynamic load improved significantly after wheelset lathing,and the number of fractures of the primary steel springs significantly decreased.Based on the analyzed results,it is suggested to strictly control the wheelset-lathing interval,reduce the dynamic stress level of the primary steel springs and extend the service life of the primary steel spring.At the same time,after summarizing the main factors and improvement measures for the fracture of offset primary steel springs in metro vehicles,it is suggested that the fatigue strength and natural frequency of primary steel springs should be increased in the design and type selection stage to reduce the occurrence of fractures.
NETL
NSTL
万方数据
维普
