Share Email Print
cover

Proceedings Paper

Large-amplitude rotary induced-strain (LARIS) actuator proof-of-concept demonstrator
Author(s): Victor Giurgiutiu; Craig A. Rogers; Shane McNeil
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

Induced-strain materials can produce very large forces and, hence, large energy density, but small actual displacements. A new concept for obtaining large-amplitude rotary displacements from small linear displacements generated by induced-strain material stacks is proposed. The concept utilizes the theory of twist-warping coupling in thin-wall open tubes. The theory of the proposed solid-state axial-to- rotary converter-amplifier, together with the appropriate bibliographical references, is given. A simple formula is generated for estimating the axial-to-rotary conversion- amplification coefficient from the geometrical length, L, and enclosed area, A, of the open tube. A large-displacement induced-strain rotary (LARIS) actuator proof-of-concept demonstrator was built and tested to verify and validate the theoretical developments. The LARIS actuator consisted of a 28 mm diameter, 1.2 m length open tube and a 120 micrometer, -1000 V PZT translator. The experimental set-up and the excitation and measuring equipment are fully described in the paper. A maximum rotary displacement of 8 degrees was measured, and the linear relationship between the rotation coefficient, the tube length, L, and the inverse of the enclosed area, A, was verified. An improved theoretical model, that accounts for the experimentally observed zero off-set, is also given. The theoretical developments and experimental tests presented in this paper show that the proposed LARIS actuator, based on a novel solid-state axial-to-rotary converter-amplifier utilizing the warping-torsion coupling of an open tube, is a viable design option, of great constructive simplicity and very low parts count. This concept can be successfully used in a series of aerospace and mechanical engineering applications, as for example in the actuation of adaptive control surfaces for aircraft wings and helicopter blades. The 8 degree rotary displacement capabilities measured on the proof-of-concept demonstrator can be easily scaled to other values to meet the operation requirements of specific applications. For very large angles (40 - 50 degrees), conventional electromechanical actuators (e.g., stepper-motors and ball-screws assemblies) can used.

Paper Details

Date Published: 6 June 1997
PDF: 11 pages
Proc. SPIE 3041, Smart Structures and Materials 1997: Smart Structures and Integrated Systems, (6 June 1997); doi: 10.1117/12.275668
Show Author Affiliations
Victor Giurgiutiu, Univ. of South Carolina/Columbia (United States)
Craig A. Rogers, Univ. of South Carolina/Columbia (United States)
Shane McNeil, Virginia Polytechnic Institute and State Univ. (United States)


Published in SPIE Proceedings Vol. 3041:
Smart Structures and Materials 1997: Smart Structures and Integrated Systems
Mark E. Regelbrugge, Editor(s)

© SPIE. Terms of Use
Back to Top