Stress Analysis of Multilayered Coatings Subjected to Surface Point Contact Loading Based on Its Three-Dimensional Elastic Field Solution

In order to investigate the effect of the structural layout of multilayered coatings on its mechanical behavior, a three-dimensional elastic field solution is developed for multilayered solids subjected to surface point contact loading, which is converted from the elastic field solution in frequency domain by using a numerical conversion algorithm. The elastic field solution in frequency domain is obtained by numerically solving a group of linear equations involving the unknown constants in the general elastic field solution of layered material that is obtained by using Fourier integral transform technique. The present solution is validated by comparing with the exact analytical solution for uncoated solids and finite element solution for solids coated with 30 layers. Lastly, the effect of structural layout of multilayered coatings is further investigated with present solution. The result shows that the gradient structural layout with elasticity modulus decreasing gradually from the top layer to the substrate, which is preferable to a larger friction coefficient for multilayered solids subjected to surface line contact loading, is preferable for a smaller friction coefficient <0.1 for multilayered solids subjected to surface point contact loading, and the gradient structural layout with elasticity modulus increasing first in the top layers and then decreasing in the bottom layers, which is preferable to a smaller friction coefficient for multilayered solids subjected to surface line contact loading, is preferable for a friction coefficient >0.2.