Abstract

Natural frequencies and frequencies of resonance in idling circular sawblades were experimentally studied. The sawblades were classified according to saws diameters, geometry of the teeth, number of teeth and height of the teeth. The excitation of the sawblades was made by means of impact, both in steady state and in rotation. The vibrations were measured using a displacement transductor, without contact and the frequency response using fast Fourier transforms (FFT). The results show that the diameter is the most important parameter; as the sawblade diameter increases the natural frequencies decreases. In rotating sawblades, natural frequencies are divided in two resonance frequencies close to one another: backward and forward traveling wave frequencies. The backward waves are proportional to the rotation speed and the forward waves are inversely proportional to the rotation speed.