Compliant variable negative to zero to positive stiffness twisting elements

Amoozandeh, A.; Herder, J.L.; Radaelli, G.

doi:10.1016/j.mechmachtheory.2024.105607

Compliant variable negative to zero to positive stiffness twisting elements

Title

Compliant variable negative to zero to positive stiffness twisting elements

Author

Amoozandeh, A. (TU Delft Mechatronic Systems Design)
Herder, J.L. (TU Delft Precision and Microsystems Engineering)
Radaelli, G. (TU Delft Mechatronic Systems Design)

Department

Precision and Microsystems Engineering

Date

2024

Abstract

Compliant mechanisms have the potential to be utilized in numerous applications where the use of conventional mechanisms is unfeasible. These mechanisms have inherent stiffness in their range of motion as they gain their mobility from elastic deformations of elements. In most systems, however, complete control over the elasticity is desired. Therefore, compliant mechanisms with variable, including zero, stiffness can have a great advantage. We present a novel concept based on the prestressing of open thin-walled multi-symmetric beams. It is demonstrated that by changing the prestress on the center-axis of these beams, a range of variable torsional stiffness can be achieved. For beams with a large warping constant, the stiffness changes from positive to zero and negative as the prestress increases, while for beams with a near-zero warping constant, the range of neutrally stable twisting motion increases. A planar equivalent is shown in this work to elucidate the notion, and numerical and experimental analyses are performed to validate the prestress-related behavior.

Subject

Bistable mechanisms
Compliant mechanisms
Negative stiffness
Twisting beams
Variable stiffness
Zero stiffness

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http://resolver.tudelft.nl/uuid:a11a1f00-5d56-432a-be7d-28cec545e835

DOI

https://doi.org/10.1016/j.mechmachtheory.2024.105607

ISSN

0094-114X

Source

Mechanism and Machine Theory, 196

Part of collection

Institutional Repository