A mechanical energy approach to predict fretting-wear damage in nuclear components

Fretting-wear damage between a vibrating structure and its supports is discussed in this paper. Typical components of concern are piping systems and pipe-supports, heat exchanger tubes and tube supports, and nuclear fuel bundles and fuel channels. Fretting-wear damage is related to the dynamic interaction between a structure and its supports. This interaction is conveniently formulated in terms of a parameter called 'work-rate' to predict fretting-wear damage. Work-rate is simply the integral of contact force over sliding distance per unit time. Fretting-wear damage may be investigated from an energy point of view. It is essentially the mechanical energy or power dissipated through contact forces and sliding that causes fretting-wear damage. Development of a simple formulation that relates tube vibration response and fretting-wear damage is presented in this paper. Several practical examples and simple calculations are discussed.