Numerous tribological contacts worldwide rely on adequate lubrication quality for proper functionality. Despite this, there is no existing approach to accurately predict the state of lubrication. The default model since introduced in the 1960s—the \(\Lambda\)-ratio, defined as the oil film thickness over the surface roughness height—is unpredictable and may yield erroneous results. Here, we put forward a framework for a new updated film parameter, \({\Lambda }^{*}\), which accounts for the elasto-hydrodynamic lubrication (EHL) effects induced by surface irregularities on the microscopic scale (micro-EHL). This new film parameter was validated in ball-on-disc tribological tests with engineering surfaces comprising isotropic and anisotropic structures. As expected, the new model was found to accurately predict the experimentally measured true mixed and full-film EHL regimes. The ability to accurately predict the mode of lubrication represents a major advance in designing tribological interfaces for optimal efficiency and durability.

世界范围内的许多摩擦学接触都依靠适当的润滑质量来实现适当的功能。尽管如此，目前还没有准确预测润滑状态的方法。自1960年代以来引入的默认模型\（\ Lambda \）-比率（定义为在表面粗糙度高度上的油膜厚度）是无法预测的，可能会产生错误的结果。在这里，我们提出了一个新的更新电影参数\（{\ Lambda} ^ {*} \）的框架，这说明了微观尺度上的表面不规则引起的弹性流体动力润滑（EHL）效应。这个新的胶片参数已在包含各向同性和各向异性结构的工程表面的圆盘摩擦试验中得到验证。如预期的那样，发现新模型可以准确预测实验测量的真实混合和全膜EHL方案。准确预测润滑方式的能力代表了在设计摩擦学界面以实现最佳效率和耐用性方面的重大进步。