Reliability assessment of hydraulic shovel system using fault trees

Abstract

The reliability of a hydraulic shovel system has been assessed through the application of fault-tree methodology. Fault-tree analysis assists in the evaluation of the reliability of a system or alternative designs and identifies critical components for system success and potential causes of system failure. It uses deductive reasoning to identify system failure. A reliability block diagram and fault tree of the shovel system were developed. An algorithm for obtaining the minimum cut set as well as the minimum path set from the fault tree is presented and the reliability of the machine and its sub-systems with time is evaluated. The analysis indicates room for improvement in different aspects of the machine.The shovel-truck combination is prevalent as a mining system in India's opencast mines. The shovel is used to remove overburden and to continuously dig, haul and load the mineral on to the trucks. For mine production targets to be achieved it is essential that the shovel be reliable and available for production.The reliability of a piece of equipment or component is the probability that it will perform a required function satisfactorily under the stated operational and environmental conditions for a specified period of time; reliability is considered to be a major barometer for the overall condition of a machine. The availability of a system is defined as the probability that an item is operating or operable satisfactorily when used under stated conditions, or as the fraction of total time that an item is available for use. It is often expressed as (Total operating time)/(Total operating time + Total downtime), with many variants.Reliability assessments of mining machines have been explored in previous publications. [1][2][3][4][5] Kumar and Mishra 1 followed a basic approach derived from system reliability theory to evaluate the reliability of a hydraulic shovel given the equipment failure data. Kumar and co-workers 2 and Paraszczak and Perreault 3 carried out a reliability-based investigation of diesel-operated load-haul-dump machines in an underground mine. In these studies general analytical techniques were used to fit a probability distribution that would characterize the failure data for the machine sub-systems and to identify the sub-systems critical for further improvement. The present authors 4,5 employed graphical and analytical techniques to study the reliability and operational behaviour of shovels and their sub-systems in an opencast coal mine with the goal of continuous improvement to the machines. The development of an adequate model and assessment of reliability by fault-tree analysis appear, however, to have been overlooked and an attempt is made here to evaluate the reliability of a hydraulic shovel system by this method.

Enhanced K-Nearest Neighbors Method Application in Case of Draglines Reliability Analysis

“…Therefore, machine learning methodologies can be applied in the mining industry in order to enhance the proactive maintenance. The best practice in the mining industry is based on the application of classical methodologies of reliability analysis, which measure the Key Performance Indicators [7][8][9][10][11][12]. In the previous studies, TBF and TBR have been applied; however, more data give more chance for making better predictive model and represents more information about status of a machine.…”

A new model for reliability design and reliability sensitivity analysis of a hydraulic piston pump

“…The research objects involve the following: structural system, mechanism system, vibration system, time-varying system, and so on. In recent decades, the reliability model of a hydraulic excavator system; Zhao et al 28 studied the reliability of hydraulic structures, considering unit hydrograph uncertainty; Samanta et al 29 assessed the reliability of hydraulic forklift system using the fault tree method; Avontuur and Van Der Werff 30 studied the reliability of a mechanical and hydraulic driving system; Yao and Zhao 31 discussed the reliability analysis and design of a synthetic rubber briquetting machine; and Burgazzi 32 studied and analysed the safety and reliability of a thermal-hydraulic passive system via application of failure mode and effect analysis.…”

“…Research on the reliability of hydraulic components and systems has developed since 1970s. Many scholars around the world have performed much work to study different aspects of such research, with the major research efforts being the model method and the experimental method of hydraulic components and systems; nevertheless, research on the reliability of hydraulic components and systems remains limited, for example, Majumdar 27 established and analysed a reliability model of a hydraulic excavator system; Zhao et al 28 studied the reliability of hydraulic structures, considering unit hydrograph uncertainty; Samanta et al 29 assessed the reliability of hydraulic forklift system using the fault tree method; Avontuur and Van Der Werff 30 studied the reliability of a mechanical and hydraulic driving system; Yao and Zhao 31 discussed the reliability analysis and design of a synthetic rubber briquetting machine; and Burgazzi 32 studied and analysed the safety and reliability of a thermal-hydraulic passive system via application of failure mode and effect analysis.…”

Optimizing replacement time for mining shovel teeth using reliability analysis and Markov chain Monte Carlo simulation

“…Reliability analysis is necessary to formulate and implement an optimum PM schedule. It has been conducted for a hydraulic shovel system using fault tree analysis (Samanta et al, 2013) and for various subsystems of a cable shovel (Roy et al, 2001). Peralta et al (2016) proposed a PM plan in which the maintenance frequency is based on the reliability of each subsystem.…”