Impact damage testing based on high-speed continuous water jet aircraft coatings

When an aircraft passes through a rainy area at high speed, the coating on the front edge of the fuselage will be continuously eroded by raindrops, causing the coating to wear, crack or even peel off. This paper uses carbon fiber T300 material as the base material, and at the different impact speeds and impact numbers, water cutting equipment was used to simulate the erosion of the coating caused by the continuous impact of water droplets. The damage morphology of samples at different damage stages was observed by digital microscope and Scanning Electron Microscope (SEM), and the damage evolution curve was established to analyze and reveal the damage behavior and damage mechanism of rain erosion. The results show that the degree of damage experienced an increasing trend with the increase of impact numbers and speed, until circular peel damage was formed; no damage occurred during the incubation period, and the curvature of the damage evolution curve increased significantly after the expansion period and eventually showed a stable expansion trend. The mechanical properties of the coating material were the main influencing factors of its rain corrosion resistance. Moreover, the axially symmetric unsteady contact problem of droplets impacting the surface of a solid deformable body was studied. And the contact area was determined based on the iterative algorithm boundary positioning method. A mathematical model and closed mathematical formula describing the unsteady interaction between a droplet and a solid deformable obstacle were proposed.