Hit Me Baby One More Time –The Do's and Don'ts of Impact and Transient Excitation Excitation

摘要

There are many types of data that can be used to estimate the modal parameters of a structure, but by far, thernmost common practice is to measure a set of frequency response functions (FRF's), that is, the response due tornan input force, expressed in the frequency domain. The input force or excitation for the FRF's can have variousrndescriptions, including broadband random, harmonic, or transient. Transient excitation is the subject of thisrnpaper. Transient input includes far more than hammer impacts, and is only limited by one's creativity and thernrequirements of the test structure. As well as hammer impacts, transient input could include step relaxation,rnprojectile impacts, explosive excitation, shaker induced transients, balloon bursts, etc. The general advantages,rndisadvantages, and pitfalls of transient excitation will be described, along with actual applications illustratingrnmodal tests that used and required some unique transient inputs.