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A new lubrication model of poroelastic lubrication of materials with low Young’s modulus and permeability is presented based on Darcy’s law and linear elastic solid mechanics and a contact model. A rotating bearing surface moving against a flat surface is considered and the effect of material parameters and operating conditions is analyzed. The results show that the material parameters (permeability ( k), Young’s modulus ( E), and viscosity ( μ)) and operating conditions (angular velocity ( ω) and material deformation ( δ)) have significant effects on the lubrication performance of the poroelastic bio-inspired materials. It is also observed that the load ratio (the ratio of pressure-borne load to the applied load along the contact boundary) increases as k and E decrease, and as μ, ω, and δ increase. Conversely maximum solid stress decreases with decreasing of E, μ, ω, δ and with increasing of k. The relationship of the load ratio, contact stress, and deformation relative to E and k has been illustrated in this paper.

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Nature has long been an important source of inspiration for mankind to develop artificial ways to mimic the remarkable properties of biological systems. In this work, a new method was explored to fabricate a biomimetic engineering surface comprising both the shark-skin, the shark body denticle, and rib morphology. It can help reduce water resistance and the friction contact area as well as accommodate lubricant. The lubrication theory model was established to predict the effect of geometric parameters of a biomimetic surface on tribological performance. The model has been proved to be feasible to predict tribological performance by the experimental results. The model was then used to investigate the effect of the grid textured surface on frictional performance of different geometries. The investigation was aimed at providing a rule for deriving the design parameters of a biomimetic surface with good lubrication characteristics. Results suggest that: (i) the increase in depression width ratio [Formula: see text] decreases its corresponding coefficient of friction, and (ii) the small coefficient of friction is achievable when [Formula: see text] is beyond 0.45. Superposition of depth ratio Γ and angle's couple under the condition of [Formula: see text] < 0.45 affects the value of friction coefficient. It shows the decrease in angle decreases with the increase in dimension depth [Formula: see text].

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