OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 25 No. 3 2023 Fig. 3. Experimental Setup these peeks, the associated natural frequencies have been extracted.The fit circle approach uses the Nyqust plot to calculate the damping factor. The fitting circle method took into account only a few places in the vicinity of the response, so the peak amplitude had little effect on the results.The location of the response peak lies on the arc of a circle when using the fitting circle approach. Fig. 5 illustrates a typical Nyqust plot using the fitting circle approach. The formula for calculating damping factor is shown in Equation 1. 2 2 2 1 2 1 0 2 1 2 tan tan 2 2 ω − ω ς = a a ω ω + ω , where ω0 = angular resonance frequency; ω1, ω2 = angular frequencies; a1, a2 = angle between angular frequencies. DEWESoft FFT Analyser Ø 8 Channel Data Acquisition System Impulse Hammer Composite Specimen Fig. 4. Freevibration setup
RkJQdWJsaXNoZXIy MTk0ODM1