534189.fig.003
Figure 3: Primary resonance, subharmonic resonance and superharmonic resonance, frequency-response curve with stability, ~ stable, unstable: (a1) conveyer empty, ( , ), (b1) slide mode, ( , ); (c1) ride mode, ( , ); (a2) conveyer empty, ( , ), (b2) slide mode, ( , ), and (c2) ride mode, ( , ). and (a3) conveyer empty, ( , ), (b3) slide mode, ( , ), and (c3) ride mode, ( , ).