Research on the contact stiffness–contact stress mapping relationship of the lubricating interface using ultrasound technique

Contact stiffness–contact stress mapping relationship is the key to ultrasonic stress measurement. The interaction of asperities at the rough interface is very complicated. The complexity of the asperity interaction and the irregularity of the lubricant film distribution make it difficult for the existing acoustic models to accurately construct the mapping relationship. Therefore, this paper conducts experimental research on the contact stiffness of the lubricating interface, and constructs the contact stiffness–contact stress mapping relationship of the lubricating interface considering the influence of plastic deformation. The critical contact pressure is determined and used to analyze the influence of plastic deformation and elastic deformation on contact stiffness. The change of equivalent oil film thickness and stiffness under load was also analyzed, and the optimized analysis formula is obtained. Based on the load sharing concept, the contact stiffness–contact stress mapping relationship of lubricating interface was constructed. Finally, the proposed acoustic model was experimentally verified. © 2023, Indian Academy of Sciences.