Structural Response and Fatigue Damage Analysis of Channel Wall Nozzle for Cold Test

In this paper, the approximate structural response of the channel wall nozzle during cyclic working process and the key impact factors affecting nozzle fatigue damage using the cold test, which has the merits of simplicity, convenience and low-cost, were analyzed. In detail, the nonlinear finite element method and the local strain method were adopted to investigate the structural response and low cycle fatigue damage of channel wall nozzle under cyclic working loads and parametric method was used to estimate the effects of different cyclic loading schemes and channel parameters (width, liner thickness, etc.) on the nozzle structural response and fatigue damage. Numerical simulation results show that structural deformation of channel wall nozzle mainly occurs in the liner region connected with the rib and the symmetry planes of the cooling channels. The residual strain in the front and middle of channel wall nozzle is larger than that in the back of the nozzle. Under the same maximum working pressure, low cycle fatigue damage of the nozzle with different cyclic loading schemes is different. With the decrease of channel width or the increase of liner thickness, both the residual strain and the fatigue damage of the channel wall nozzle decrease.