Fracture behaviours of brittle ceramics under elliptical ultrasonic vibration: near-to-limit contact analysis of an elastic flat punch

Conform and non-conformal contact problem in the face of piezoelectric motors can be hard to grasp, especially both the friction drive and wear lifespan are considered. Flowing the classical contact issue, an elastic brittle flat punch as the driving tip of the stator for piezoelectric devices is chosen and the contact behaviour under elliptical ultrasonic vibration is investigated using finite element method. A limited stress analysis is conducted after the quasi-static contact of the driving tip and the slider of the linear ultrasonic motors. After the analytical traces and experimental test on the fracture failure induced by the stress actions, the failure criteria of the elastic brittle driving tip are discussed. Results show that this quasi-static method can be applied to the complex contact analysis of an elliptical vibration device, and the failure characteristics induced by stress and strain can be obtained by FEM simulation and experiment verification. The pre-fracture stress map provides an important basis for the design of the geometrical mutation edge (e.g. edge fillet) of the elastic brittle punch and the composite structure for strength capacity. The failure analysis of brittle materials under ultrasonic vibration requires attention on quasi-brittle and quasi-plastic strength criterions. This study focus on determination of the contact stresses and the limited states during the elliptical vibration of a stator tip against slider. It also is important for the analysis on failure modes of frictional materials of ultrasonic devices, fretting wear of high-frequency connecting parts and machining process assisted with ultrasonic vibration.

Automated summary

This study investigates the contact behavior and failure characteristics of the driving tip in piezoelectric devices under elliptical ultrasonic vibration, providing important basis for the design of composite structures and discussing the failure analysis of brittle materials under ultrasonic vibration. The results show that quasi-static method and FEM simulation can be applied to complex contact analysis and obtaining failure characteristics induced by stress and strain. Additionally, the study emphasizes the importance of attention to quasi-brittle and quasi-plastic strength criterions in failure analysis under ultrasonic vibration.