Miniature hourglass shaped actuator geometry study using a finite element simulation /

Bibliographic Details
Main Author:	Elwell, Roston Clement
Other Authors:	Creasy, Terry S. (Thesis advisor)
Format:	Thesis eBook
Language:	English
Published:	[College Station, Tex.] : [Texas A&M University], [2011]
Subjects:	Major mechanical engineering. Morphing Structure Miniature Actuator Machine Augmented Composite
Online Access:	Link to OAK Trust copy

Description
Abstract:	This project investigated a miniature, hourglass-shaped actuator (MHA) and how its geometry affects performance. A custom, self-contained, finite-element simulation code predicts how each MHA deforms when pressurized internally. This analysis describes the MHA geometry's effects on four characteristics: a) work density b) mechanical advantage, c) work advantage and d) percent elongation. The first three characteristics are compared to a traditional actuator operating at the same pressure and elongation. A finite-element modeling code was tailored to study the MHA at 5 MPa internal pressure when 1) MHA height and side-wall thickness are constant and side-wall arc length varies; 2) MHA side-wall arc length and thickness are constant and the height varies; and 3) MHA side-wall thickness varies while height and side-wall arc length are fixed. Case 3 was studied using the MHA geometry with the highest work density found in either condition 1 or 2. Peak mechanical advantage, 6.47, occurs in a constant height MHA--Case 1--when the side-wall arc length is shortest. Highest elongation, 8.67%, occurs in the Case 1 MHA with the longest side-wall arc length. Finally, under Case 3, work density reaches 0.434 MJ/m³ when the side-wall thickness is 1.9 mm. The MHA has potential for active structures because its work density is high--higher than traditional actuators with the same elongation. Their small elongations limit their use; however, much work remains to determine how MHAs might be arranged in a useful array. Never the less, morphing airfoils and other active structures might benefit from embedded MHAs.
Item Description:	"Major Subject: Mechanical Engineering" Title from author supplied metadata (automated record created 2011-08-09 15:09:44). Electronic resource.
Physical Description:	1 online resource.
Bibliography:	Includes bibliographical references.