The Multi-Objective Optimization Of Maintenance Period Of Construction Machinery

With the development of the network economy, the competition among enterprises becomes more violent, in order to improve productivity and market competition of the whole enterprise, more and more enterprises start realizing the importance of research and implement of maintenance management. By analyzing the necessity of maintenance of construction machinery, this paper discusses the periodic maintenance affecting the performance of the construction machinery and investigates the dynamic rule of failure rate in the maintenance. Based on this dynamic failure rate, this paper studies the optimization theory and method of maintenance period under single objective and multi-objectives.At first, this thesis discusses the present situation of optimization of maintenance period of construction machinery in domestic and foreign country, and puts forward the necessity of maintenance optimization. After systematical analysis of the present situation of maintenance management of construction machinery of our country, system of maintenance management, the process of failure and the rule of failure, proposes the main problems existing in the maintenance management of the construction machinery. Combining the domestic and foreign present research situation, adopts least square method to analyze historical failure data of construction machinery, and to fit the failure rule of the best distribution of construction machinery.By analyzing the effects of five different types of maintenance operation, this thesis proposes the conception of metabolic failure rate, and introduces age reduction factor to represent the effect of periodic maintenance, and analyzes thedynamic rule of failure rate of construction machinery changing in the process of maintenance and operation. Through establishing the maintenance model based on safety service level, discusses the connection between safety service level and maintenance period and the changeable rule of different maintenance period under dynamic failure rate. On the basis of the availability model of dynamic failure rate, analyzes the maintenance period in the principle of maximum availability, the rule, the changeable trend of different maintenance period and the cumulate availability. Based on the cost model of unite time, investigates the connection between unit time and maintenance period, and educes the best maintenance period of minimum unit time and the connection between different maintenance period.Based on the single-objective maintenance period model, establishes a multi-objective maintenance period mathematics model synchronously considering the factor of safety service level, availability and cost. Analyzing the optimization method seeking multi-objective problem, adopts a multi-objective genetic algorithm and program to seek the outcome and obtain the best multi-objective outcome of maintenance of construction machinery.