Summary
In this work an exact expression is derived for the fold (jump-down) point of the main harmonics of frequency response curve on the model of harmonically excited single degree of freedom viscose damped Duffing oscillator. The derivation is made based on the Poincare expansion method. In its leading term it provides an exact solution for the fold frequency point which then can be used for predicting hysteresis bandwidth depending on the nonlinearity, the static deflection and the viscose damping factor.
