摘要: An inverse coefficient problem for a variational inequality arising in the elastohydrodynamic lubrication of a journal bearing is presented. The height of the gap between two rotating surfaces denotes the distributed parameter that has to be estimated from measurements of the pressure in the lubricant between the surfaces. The variational inequality approach which includes the phenomenon of cavitation, ie the situation where the gap is not entirely filled by the lubricant, reduces to the Reynolds lubrication equation under fully-flooded conditions. Utilizing a regularized least-squares formulation the problem of existence of multipliers, and the importance and derivation of a first order characterization amenable for (structured) numerical realization are addressed. Many concepts known from the literature fail in one of these aspects. The usage of complementarity functions turned out to be important. Finally, the …