Reliability Analysis of Dragline Using Equivalent Aging Model

Traditional models for reliability analysis of mining equipment are developed from time to failure data. However, inclusion of operational data and environmental stressors in reliability analysis makes models realistic and can predict the reliability as well as availability of equipment more precisely. It also allows us to understand the aging process of the equipment. The aging of equipment can be comprehended with the concept of the equivalent age that describes how much the equipment wear-out within a particular duration when it works under a specific environmental condition. Thus, equivalent age differs from its physical age. This study has used last 12-year operational data of a dragline deployed in a large opencast coal mine. Collected data have been grouped into four maintenance strategies. It is revealed from the results that production stress and maintenance strategy significantly affect the equivalent age of the dragline. Moreover, the effect of maintenance has been incorporated intrinsically in the equivalent age model to represent a gradual effect of a particular maintenance strategy on dragline aging. This research has studied the effect of a set of maintenance strategies and production stress on the reliability of a dragline using the concept of equivalent age. This concept will help the maintenance engineers in preparing a suitable maintenance plan for the draglines or any heavy earth moving machines in advance.