Wear depth model for thin tubes with supports

A wear depth prediction model is proposed for thin tubes worn by a contact with supports. It has the form of D˙=Kw˙ where D˙ and w˙ are the wear depth and the energy density rates, respectively; K is a wear coefficient with the unit of Pa−1. Two kinds of experiments, i.e. sliding and sliding/impact are conducted with the fuel rod tubes and the transversely concave-contoured supports under room temperature and air/water environments. The applied sliding amplitude was 50-100 μm and the contact normal force was 10-50 N in the sliding wear experiment. Impact force of around 30 N was applied in the sliding/impact wear experiment. It was found that a linearity between D˙ and w˙ exists at the same contact normal force condition. In the sliding wear experiments, K is larger in the air than in the water environment. It was verified that the addition of an impact is detrimental to a wear failure than a sliding wear only. It is thought that K can represent a wear resistance parameter in the point of the wear depth when the wear mechanism is similar. The influence of wear debris dispersion behaviour on the present model is discussed.