Look at the ratio of idler frequency to belt frequency. Idler frequency is just the frequency of the rotation. Belt frequency is trickier. Start with beam equations.

or just buy some software that computes all this kind of thing for you. The company I work for, Conveyor Dynamics, sells software to do this. ■

All the formulae for belt resonance has been covered very well by Prof Alec Harrison.

You can find this information in his papers presented at the very early Beltcons.. all available on the web.

Cheers

LSL Tekpro ■

Beam equations are better than string vibration equations to predict belt frequencies, BUT most modern conveyors use V-returns and so whoever suggested you look at beam equations will lead you to wrong results.

Plate mechanics and resonance excitation (which is generally non-linear due to hardening restoring forces) are required to predict belt flap frequency of a given span, idler diameter belt speed, belt tension and the bending siffness of the orhogonal plate with at least 4 mechanical boundary conditions specified. You need to be able to correctly predict the values of the non-dimensional frequency parameters of a 4-th order PDE. You will also need to know the belt properties and mechanical Q of the belt under dynamic conditions.

See Graham Spriggs comments also.

Consult papers : Phil. Trans. of the Royal Society, 1991, and some early (~ 1983 - 1989) Bulk Solids Handling papers (Harrison). ■