光电跟踪与测量技术研究室知识库

As a driving unit and core component of the acquisition, pointing and tracking (APT) system's fiber actuator, the fatigue mechanism and fatigue life analysis of the piezoelectric ceramic tube (PCT) nutator in a high-frequency dynamic state have become one of the urgent research issues in the reliability field of interstellar laser communicating key devices. This article commences by elucidating the principles of deflection and nutation of the PCT nutator. Subsequently, employing finite element simulation methodologies, an exhaustive analysis is conducted to discern the stress and strain energy density distribution within a single operational cycle under specific working parameters. The findings illuminate the principal fatigue failure mechanism of the dynamic piezoelectric ceramic tube, characterized by crack propagation and eventual rupture resulting from localized stress accumulation during dynamic processes. Furthermore, the coordinates of the "most dangerous element" are ascertained, and a fatigue life model for the PCT nutator in transient nutation is proposed based on the theory of material fatigue damage accumulation. Based on model calculations, the theoretical fatigue life of the PCT nutator can reach 2.31×106 cycles under the environmental conditions with a 500Hz bandwidth and maximum nutation radius.