PSI - Issue 59

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Ivan Shatskyi et al. / Procedia Structural Integrity 59 (2024) 407–412 Shatskyi et al. / Structural Integrity Procedia 00 (0000) 000 – 000

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Fig. 2. Distribution of equivalent stress along the faces of the layers; solid lines are for the upper and dashed lines are for the lower faces.

0  x .

Fig. 3. Distribution of equivalent stress over the thickness of the three-layer coating at

Fig. 4. Distribution of the safety factor over the thickness of the three-layer coating at 0  x . As can be seen from Figs. 2, 3, the stress state is concentrated in the vicinity of the line of application of the concentrated force, and the highest equivalent stresses are observed on the lower face of the nickel layer (on the line 0) ( , ) (0, 1 2    h h x y ). Since we are dealing with a nonhomogeneous coating, in order to assess its limit state, one should also take into account the spatial distribution of strength characteristics (in this case, the value of the yield boundaries of each layer). Therefore, a more correct characterization of the boundary state of a layered coating is given by the distribution of the safety factor (Fig. 4). Despite the fact that the maximum equivalent stress is reached in the nickel layer, the limit equilibrium of the coating will be violated first on the surface of the chrome layer, where the safety factor is the smallest.