STRESS INTENSITY FACTOR FOR A SINGLE-EDGE NOTCHED SPECIMEN SUBJECTED TO RESONANCE VIBRATION AT ULTRASONIC FREQUENCIES

The stress intensity factor of a single edge notched specimen is deter mined for push-pull loading by resonance vibration. The calculation is performed by a finite element analysis program. Stresses as well as r esonance frequency are approximated by the inverse iteration method. T o determine the K(max) values, material parameters, crack length and t he vibration or the velocity amplitude of the specimens are used. Meas urements of the fatigue crack growth rates at nominal constant stress intensity amplitude show that the resulting crack growth rate is indep endent of the crack length, thus verifying that the proposed calculati on procedure is correct.