影响超磁致伸缩执行器中逆效应性能的主要因素

超磁致伸缩材料(GMM)是一种具有双向可逆换能效应(磁-机、机-磁)的新型功能材料,利用其逆效应在超磁致伸缩执行器(GMA)驱动过程中感知出传感信号,可实现自感知执行器.探讨超磁致伸缩逆效应的机理,设计一种试验方法,验证了超磁致伸缩执行器中的磁致伸缩逆效应.揭示预压应力、偏置磁场和激振力频率等因素对超磁致伸缩逆效应性能的影响规律,预压应力越大则逆效应性能越差,适当的偏置磁场可使逆效应性能显著增强,激振力频率越高,力感知灵敏度越高,但不成简单的正比关系.试验证明了GMA作力传感器有效性,提出一种分时结构的自感知GMA.

MAIN FACTORS OF CONVERSE EFFECT PERFORMANCE IN GIANT MAGNETOSTRICTIVE ACTUATOR

Giant magnetostrictive material (GMM) is a new functional material which has reversible dual-directional transduction effect (magnetic to mechanical and mechanical to magnetic). If the sensing signals based on inverse magnetostric-tion could be attained in the driving process of giant magnetostrictive actuators (GMA), the self-sensing actuator would berealized. The origin mechanism of magnetostrictive converse effect is discussed. An experimental method to test the converse effect in the GMA is built up. The influence of pre-stress, bias magnet and drive force's frequency to the converse effect in GMA is disclosed. The inverse effect changes weaken while increasing pre-stress, and appropriate bias magnet can enhance the inverse effect observably. The sensitivity of force sensing signal is improving with the increasing of vibration force' s frequency, but the relationship is not ordinary linear. Experi-ments validated that GMA could be used as force sensor, and a self-sensing GMA based on time-sharing theory is pointed out.