Research On Preventive Maintenance Decision-making Of FPSO 116 Based On Remaining Life Prediction

With the rapid development of ship manufacturing industry,the number and scale of ships are growing rapidly.However,some equipment on the ship are scrapped before it reaches the end of service life.However,some equipment on the ship are scrapped before it reaches the end of its service life.This is due to negligence in the maintenance of the equipment.As a result,it leads to a serious decrease in the reliability of the equipment on the ship in a short period of time.These will not only threaten the safety of ship navigation,but also cause great resources waste.It is necessary to optimize the process of ship maintenance.Thus,we study the development and selection of cabin structure maintenance strategies by using theoretical analysis and numerical simulation.In this thesis,the deterioration process of cabin structure is studied from the perspective of timeliness and maintenance cost.A state prediction based visual maintenance model is constructed,using the idea of Markov chain.The strategy for situational maintenance is selected according to the speed of state transfer rate.It is proposed that when structures in the range of 50%--70% deterioration at maintenance,there is a nearly 70% probability that can be restored to new or repaired to a good condition.Secondly,considering the influence of part status,demand variation and cost on strategy selection,a preventive maintenance decision model is developed.The maintenance interval and the remaining life threshold are used as optimization variables,and the minimum average maintenance cost rate is used as the objective function.The model is solved by using the PSO algorithm and it is concluded that it is a more economical solution to perform preventive maintenance when the structural condition is close to failure.Finally,the cost is solved by applying the whole life cycle cost-benefit analysis method in combining specific maintenance measures.The results show that the direct replacement option is the least expensive in the early stages of maintenance.However,as the service time increases,the cost of preventive maintenance measures such as rust removal and painting is less than the cost of other strategies.In addition to maintenance costs,small changes in interest rates also have a large impact on the life cycle costs.The preventive maintenance model based on the remaining life prediction is proposed in this thesis.And the simulation experiment is carried out with the calculation example of FPSO 116.The feasibility and validity of the maintenance optimization model are also validated.It not only helps to reduce the maintenance cost of cabin structures,but also provides a theoretical reference for the development of ship maintenance strategies in practice.