The damping ratio of 0.1 indicates that the system is lightly damped, meaning that it is less able to absorb shock from external influences. The stiffness of 0.2MN/m indicates that the shaft is low stiff, meaning that it is less resistant to bending or twisting forces.
The combination of the low stiffness and the light damping ratio mean that the shaft will be prone to vibration and torsional fatigue. In order to reduce the vibration, the shaft should be reinforced with more rigid material, increasing the stiffness. Additionally, a damping device such as a damping sleeve should be attached to the shaft, increasing the damping ratio and providing additional shock absorption.