Because of the limitations of a singleexpert system or neural network system in fault diagnosis, a new integrative fault diagnosis expert system which combines neural network technique with expert system is proposed. This system is applied in the mechanical breakdown diagnosis of CNC machine. The structure, characteristics and diagnostic methods of the neural network expert system are introduced. The system is verified based on the knowledge of machine failure and sampling data of faults. The result shows that this system has friendly interface and is easy to handle. It raises the level and efficiency of mechanical fault diagnosis of CNC machines.

The quasioval iced conductor model was tested in TJ2 wind tunnel to obtain aerodynamic force coefficients by using HighFrequencyForce Balance (HFFB) technique. The calculating theory of galloping characteristics of SDOF is derived, which take account of natural vibration characteristics of transmission line. The effects of wind velocity, sagspanratio, span, conductor diameter on galloping critical wind velocity and amplitude are studied and approximate method to calculate galloping characteristic of quasioval iced conductor are presented at last.

Based on Fluent 6, numerical simulation code for solving aeroelastic problems is first presented by using loosely coupled method in this paper. The fluid domain can be solved by adopting serial or parallel computation method, and the structure domain is solved by adopting Newmark method, and finally the interface coupling between the fluid and structure domains is implemented through dynamic mesh technique. The calculation process and the special method to deal with the parallel computation in fluid domain are then introduced. Finally, numerical simulation of vortexexcited vibration of a 2D square cylinder at Reynolds number of 22000 is done. The computed results and the comparison with those in literatures could verify the validity of the present program.