FREQUENCY-DOMAIN STRESS INTENSITY CALIBRATION OF DAMPED CRACKED PANELS

This paper discusses two schemes for doing finite element K calibratio n in the frequency domain. The baseline scheme uses the definition of K as a limit toward the crack tip. The limiting process requires using a very fine mesh around the crack tip making the scheme computational ly very expensive. It is shown that the behavior of K as a function of frequency is very similar to a modal response. Taking advantage of th is, a more efficient scheme involves a modal analysis of the cracked s heet and scaling the response to that of the static stress intensity. In this way, only a static K calibration need be performed. All the ex amples shown are for a frequency range spanning multiple resonances an d with two levels of damping.