On the effects of production and maintenance variations on machinery performance

The variations introduced during the production and maintenance of rotating machinery components are correlated with the vibration and noise emanating from the final system during its operational lifetime. Vibration and noise are especially unacceptable elements in high‐risk systems such as helicopters and aircraft engines, resulting in premature component degradation and a potentially unsafe flying environment. In such applications, individual components often are subject to 100 per cent inspection following production and during operation through rigorous maintenance, resulting in increased product development cycles and high production and operation costs. In this work, the aim is to provide engineers with a technique to evaluate vibration modes and levels for each component or subsystem prior to putting them into operation. This paper presents a preliminary investigation of the correlation of manufacturing and assembly variations with vibrations, using an experimental test rig. A factorial design is used to study the effects of various factors. Challenges in developing a process monitoring and inspection methodology to predict performance quality are identified, followed by a discussion of future work.