Ship Overall Reliability Of The Generic Model And Ship Reliability Engineering Methods

Naissance in the middle of last century, reliability theory has been highly developed and used in various engineering areas. Combining reliability theory with ship engineering process comes a new engineering area, ship reliability engineering.Warship is a large complex system. Determined by the natural of warship, reliability theory has an important meaning to warship. When in use, the ship will be independent from the base and sould not be supported at once while some faultures happen. The faultures of some vital components would lead the damange of the ship. On the other hand, the weekness of ship reliability would course the increase of maintenance cost and maintenance time, and then decrease the useability of the ship. So nowadays, ship reliability is highly regarded from the beginning of the design work.Like the speed of a ship, ship reliability is one of the inner characteristic of the ship. So the general method to ensure ship reliability is to process ship reliability engineering.The proces of ship relioability include reliability reasoning, reliability allocation, reliability prediction, reliability management and reliability evaluation. Caused by the special natural of large in scale, complex in structure and mission and less in producation output number of ship, the repairable system model and small sample condition are two key problems in ship reliability engineering. These two problems are also reconazed as the most difficult problems in reliability area. So the ship reliability engineering work are not as satisfied as that in some other fields. The main resons are lack ship reliability model and lack of the evaluation methods under small sample condition.Based on the research on the development of reliability model boardly, this thesis suggested a general reliability model based on fault tree. In calculation with this model, a method to deal with repairable system, reliability simulation based on minimum cut sets, will also be discussed. In large complex system reliability evaluation, a reliability evaluation method based on equivalent fault tree has been developed. At the same time, a unimodel method has been discussed to trans the models between reliability border diagram and fault tree and make more user can use the general ship reliability model and the calculation methods. At the end of this thesis, some study cases have been demonstrated to discusse the use of the general model and the calculation methods in ship reliability engineering. The main contribution of this thesis is:On ship reliability model, this thesis developed a general model to describe the characteristic of ship reliability.On repairable system reliability calculation, this thesis developed a method of reliability simulation based on minmum cut sets and resolved the problem of repairable system reliability calculation.On reliability evaluation, this thesis developed a large complex system reliability evaluation method based on equivalent fault tree to make the evaluation more creditable.To make more people use the methods, this thesis developed a method to trans the models between reliability border diagram and fault tree.Most of the methods discussed in this thesis has been used in warship engineering in our country.