Impact testing and its applications, part II

The effects of structural resonances on rotating machinery can reduce machine life and machine performance dramatically. Impact testing aids in understanding how forces are transmitted throughout a structure or mechanical system. In Part I of this paper impact testing setup, frequency response function, signal processing, data integrity checking, using the coherence function, and three types of testing problems are discussed. In Part II measurement considerations, including transducer mounting, data display, and static and dynamic stiffness, will be discussed. Two case studies of impact testing on machine tool spindles will show that impact testing can troubleshoot vibration problems effectively in machine tool applications.