a propshaft assembly includes a shaft structure having a hollow cavity and an insert member being positioned within the hollow cavity and engaging the shaft structure . the shaft structure vibrates in response to receipt of an input of a predetermined frequency such that a shell mode anti - node is generated . the insert member is located at a position that approximately corresponds to the anti - node and has a compressive strength that is tailored to an anticipated displacement of the anti - node to thereby attenuate vibration of the shaft structure .