A dynamic design method is proposed for graduation variable speed shaft.The finite element model is used for a horizontal-axis vibration.According to the sensitivity of the modal frequency to the structure size
dynamic performance parameters are changed in order to bring axis previous bands or certain frequency bands modal happening in a group of pre-specified expectations
much solution is got.Consideration the structure craft
by the optimization methods
the minimum amount of dynamic performance are obtained.The methods can also be used for other dynamic vibration system design.