MECHANICAL SYSTEM DESIGN IN RELIABILITY

Abstract

In this thesis a multistage compressor system is designed using Markovian approach with the purpose to improve its reliability. The design analysis helped in identifying the key factors that affects the system reliability and there exists good scope to improve the system reliability by controlling the contributing factors. Different models are developed for the system to achieve the reliability goal by adding standby redundancy to the system components. All the feasible states and, failure and repair transitions are identified to develop the system model. Keeping in mind the limitation of the Markov model the failure and repair rates are taken as constant. The sets of ordinary differential equations are obtained for the change of probability of being in respective system states with respect to time in each model. The system of rate equations is solved using Runge – Kutta method in MATLAB. The system reliability assessment is based on the sum of probabilities of all working states. Sensitivity analysis is also carried out by varying the repair rates of constituent components in the system. These results are helpful to design the highly reliable systems for thermal power plant, machineries used in medical field, aerospace and aviation industries..