Study on failure probability of passenger bogie frames

Most factors determining the reliability of passenger bogies are of random nature (load, boundary condition, etc.). The paper presents the results of a study on elements of the bogie frame structures of wagons operated in Bulgaria that has been carried out to determine reliability indicators such as failure intensity as well as mathematical expectation. To determine the distribution law of work until failure, failure data of carriage bogie elements are processed by adequate software. Graphs based on a statistical model have been constructed and reliability indicators have been analyzed. The type of distribution law of work (working off) until the passenger bogie frame failure has been determined. Based on the obtained dependences, it is possible to forecast the failure intensity for the respective passenger bogie structure at certain mileage. The discovery of unreliable bogie frame units makes possible to determine the trends of future design, production and technology activities for carriage modernization as well as the need to develop new designs of bogie frames.