A Protective Piezoelectric Actuator With Preload Retention

When aircraft operate in critical space environments, their internal piezoelectric actuators are subjected to low temperatures and strong magnetic fields, leading to reduced output displacement, force, and accuracy. This article proposes an integrated flexible mechanism utilizing the principle of cold shrinkage, capable of maintaining pretension at low temperatures, and unlike segregated flexible mechanisms, it does not lose function due to pretension failure at extremely low temperatures. First, the working principle of piezoelectric actuators with thermomagnetic protective devices in low-temperature environments is clarified, the motion process of the piezoelectric actuators is introduced, and a simulation analysis of the cold shrinkage process of the low-temperature flexible mechanism is conducted. Then, by calculating the effects of magnetic shielding and thermal protection, the feasibility of the thermomagnetic shielding device is determined. Finally, the feasibility of maintaining a constant state under different temperature conditions is experimentally verified. This research provides guidance for the shielding and protection of piezoelectric actuators operating in harsh environmental conditions.