Abstract: The method of multiple scales is adopted to investigate the combination resonances of elastic linkages under the inertial forces. The analyses have demonstated that the combination resonances caused by the internal resonance in the form of ω2=2ω1, the cubic nonlinearities due to large elastic deformation of flexible links, and multi-frequencies of the inertial forces of linkages are the reason to lead to nonsynchronism of lower order harmonic resonances of elastic linkages.

Key words: Combination resonances, Elastic linkages, Lower order harmonic resonances, Method of multiple scales