AN ENGINEERING MODEL FOR PRESSURE ASSESSMENTIN ROUGH CONTACTS

In many scenarios involving mechanical contacts loaded in the elastic-plastic domain, finding the pressure distribution and the related stresses without a detailed description of the plastic strains may be a sufficiently good approximation for the contact problem solution. This approach is considered in this work, which aims to achieve a rapid solution for the pressure distribution in elastic-plastic contacts without the solution of the residual part: the influence of the plastic strains on the contact geometry, i.e., the residual displacements, and on the subsurface stresses, i.e., the residual stresses, are not accounted for. Experimental works and numerical approaches from the literature prove that the pressure in elastic-plastic contacts is limited to roughly three times the yield strength of the softer material. The latter threshold is introduced in a previously developed computer code for the purely elastic contact, as an additional restriction. The elastic-plastic pressure is calculated from the solution of the purely elastic problem, but it is not allowed to exceed the aforementioned limit. Considering the iterative nature of the original elastic solver, algorithm convergence is not affected by the additional restriction. The technique is firstly applied to a Hertz-type contact to prove the solution viability. A roughness sample is then processed with the newly advanced computer program. The resulting pressure distribution is compared to the purely elastic case. Considering that the former was achieved with the same computational effort as the latter, it is clearly a more convenient solution for practical engineering purposes.