Yunyun Sun

TL;DR: In this article, the statistical asperity microcontact models in combination with the acoustic spring model and the load sharing concept are utilized to study the interfacial normal contact stiffness, and a load sharing approach is proposed to study interfacial contact stiffness.

TL;DR: In this paper, an elastic interface model is developed to theoretically analyze the contact stiffness of a mixed lubrication surface where the solid and the lubricant contacts have to-be-determined contributions to the whole contact stiffness.

TL;DR: In this article , a fractal contact stiffness model is proposed based on the length scale of microscopic asperities, by which the inherent nonlinear relationship between contact force and contact stiffness is revealed.

TL;DR: In this paper, an internal microdefect detection method based on an ultrasonic scanning microscope was proposed, which comprises the steps of (1) performing hierarchical X scanning on a whole sample through a low and medium-frequency ultrasonic transducer; (2) swapping a high-frequency transducers, and focusing the high-fraction transducers to an interesting local defect position; (3) setting a data gate position and data gate width for local C scanning respectively according to imaging depth and single-layer imaging thickness; (4) obtaining maximum peak values Pmax of

TL;DR: In this article, a semi-analytical model was proposed to evaluate the interfacial stiffness ratio of stationary contacts between rough surfaces, where the rough contact interface was described as a homogenized thin layer with effective moduli, which were employed to characterize the ratio of the tangential to normal contact stiffness.