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The authors thank Dr. Etsion’s interest in the paper. We agree with Dr. Etsion that with a higher contact pressure a smaller contact area is required to support a given load. However, whether asperity yielding would require less contact area to support a given contact load depends on what particular problem one studies and what assumptions one makes. This statement is clarified by two types of problems described below.
The first type of problems is a rigid flat in contact with two rough surfaces (i.e., two separate contact problems). Both the rough surfaces have the same material properties but different roughness. Then, for a given load applied to the two contact systems, the one that generates more plastic deformation is likely to (but not always) yield less real area of contact. The result is consistent with Dr. Etsion’s assertion.
The second type of problems is a rigid flat in contact with two rough surfaces, where both the rough surfaces have identical roughness, but one is elastic-plastic and the other is assumed to be perfectly elastic regardless of contact pressure. Then, for a given load applied to the two contact systems, the one that generates plastic deformation would yield larger area of contact. The result is against Dr. Etsion’s assertion but meets the fact that with a higher contact pressure a smaller contact area is required to support a given load.
The results presented in Fig. 5 of the current paper are for the second type of problems. For this type of problems, it is necessary that any micro-contact models with plastic deformation yield larger contact area than the GW elastic model. It is this analysis that leads us to conclude that the CEB model could yield physically unreasonable results.
