Performance simulation of metal hydride based helical spring actuators during hydrogen sorption

Abstract

Self sensing/actuation materials are known as smart/intelligent materials due to their changes in structure and functionality based on external stimuli. Even though, metal hydrides are studied extensively as potential materials for hydrogen storage, their applicability becomes limited due to low gravimetric storage capacity. However their significant volumetric dilatation upon hydrogenation can make them potential candidates for sensors/actuators. As hydrogenation performance of these alloys is controlled by heat transfer as the major factor, devices based on this can be employed as thermal sensors/actuators. However response characteristics of such devices need detailed investigation. A numerical study is conducted on the performance of these actuator elements with LaNi5 as the hydrogen storage alloy. Effects of different operational and geometric parameters on hydrogenation and actuator displacement are studied.