Winder drum shaft fatigue life investigation

Winder drum shaft failures have been occurring with increasing frequency in the South African mining industry over approximately the past ten pears. Consequently an investigation was defined and proposed by Angle American Technical Services (AATS). This was commissioned by the Chamber of Mines acid electively funded by industry. The paper describes the drum shaft fatigue life analysis component of the investigation, based on the Wang-Brown shear strain theory for combined bending and torsional stress. Some results of the operational drum shaft strain measurements were used to calibrate the theoretical model. Remnant life of longitudinally and of circumferentially cracked shafts is assessed using fracture mechanics theory and the significant influence of drum shaft alignment is defined. It is concluded that generally winder drum shafts should have an infinite fatigue life provided that alignment is maintained within specified limits. A cracked shalt could be kept in service subject to analysis and careful monitoring.