One of the problems in which the wear of the gas turbines constructive parts plays a fundamental role is the problem of their replacement and maintenance. This practical problem is directly related to the theoretical study of the constructive parts renewal. Such a study requires the determination of the renewal function. It is difficult for the case considered to determine it analytically. The objective of this research is to work out a standard process of evaluation of the renewal function by a single program for various strategies of maintenance, based on the Monte Carlomethod.

The statistical simulation presented in this work makes it possible to evaluate the average numbers of breakdowns and the number of repair of the gas turbines for periods of inspections and operating time intervals given. These results make it possible to release the optimal policy of maintenance and to evaluate the volume of corresponding repair work spare parts.

The state of a part is determined periodically by the parameter h. If according to the result of the inspection the part is in the state  then its repair is planned. The state  of a part appears by stopping the turbine. The periodic inspections are regarded as a filter of which the probability of passing through, i.e. to exceed the threshold  varies according to the character of the process, of the filter density, the frequency of the inspections and the fixed margin

The use of the Monte Carlo method makes it possible to work out a standard process of the renewal function evaluation by a single program for the various strategies of gas turbines maintenance as a result of simulation on the interval of time  given the average numbers breakdowns, preventive interventions and the summary number of renewal process replacement of each type of parts. That is the required evaluation of the renewal function for one period of inspection given in particular for the parts is subjected to a replacement at fixed age. One evaluates  while posing  by taking the period of inspection equal to the age of the part replacement. To evaluate  parts whose strategy of maintenance does not envisage a replacement at age fixes one poses  and  one obtains in this case the number of breakdowns and periodic parts replacements.

The elaborate algorithm makes it possible to analyze and compare the various strategies of maintenance applicable to the gas turbines. The evaluation of the renewal function makes it possible thereafter to determine the structure of the gas turbine cycle repair. The latter is necessary to choose the parameters of a maintenance system in the event of a project or to improve the programmes of an existing maintenance system.

The present study aims at finale the search for such mode of periodic inspection ensuring a profit of equipment reliability exploitation.

renewal function, optimal maintenance policy, strategy, equipment reliability of exploitation, Monte Carlo method.