Impact Energy Model Research Articles

An energy analyzing method for the assessment and diagnosis of rub–impact fault in a rotor system

An energy analyzing method called the Impact Energy Model (IEM) is introduced to assess and diagnose the rub–impact fault of a rotor system. The main purpose of the model is to indicate the probability of rub–impact or the severity level of the fault. Utilizing the nonlinear predictive energy, an effective quantitative evaluation index IEM is obtained from the model. Some work has been done elsewhere to partly demonstrate the IEM through experiments. In this paper we mainly discuss the variation of the IEM index with the speed ratio Ω at different levels of damping ratio ξ. The stagnation point is discussed in detail which is important to the assessment for the probability or severity of a rub–impact fault. The influence of dynamic stiffness is discussed which may affect the assessment result of the IEM. Furthermore, a sensitive area of the rotor operating system is presented. The result shows that this sensitive area provides a reference for the operation and design of a rotor system.

Experimental validation of impact energy model for the rub–impact assessment in a rotor system

An experimental setup which can simulate the rotor-to-stator rub in a rotor system is installed. A rub screw is used to simulate the condition of local rub–impact fault. Based on the theory of elastic collision and energy conservation, an Impact Energy Model ( IEM) is proposed to evaluate the probability or severity of rub–impact fault. To prove this model, the paper conducts the experiment in two steps i.e. hammer test and rub–impact fault validation. The wave signal, spectrum and axis orbit are used to analyze the severity of the rub–impact fault when it occurs. The analysis result shows that the proposed Impact Energy Model ( IEM) is effective in the assessment of rub–impact fault. Furthermore, the proposed IEM can also provide a reference for the design and operation of a rotor system.

Impact energy model based research of nonlinear rub-impact assessment

An impact energy model (IEM) is proposed for the research of nonlinear rub-impact assessment in this paper. According to the characteristic of the model, IEM index is given to evaluate the severity or probability of rub-impact fault. We investigate the trend of variation of IEM index response to the rotation speed ratio under the condition of different values of damping ratio , and then acquire a joint distribution of IEM response with the parameters of and . Combining the IEM model, a concept of sensitive area is proposed. The sensitive area provides an excellent reference for operating rotor system and a guidance and assessment for designing rotor system.