Title: Shape control of a beam consisting of triangular meso-structure segments with multiple V-shaped flexure springs

Authors: Luke Berglind; Jaehyung Ju; Joshua D. Summers

Addresses: Department of Mechanical Engineering, University of North Carolina Charlotte, Duke Centennial Hall, Rm 167, 9201 University City Blvd, Charlotte, NC 28223, USA ' Department of Mechanical and Energy Engineering, University of North Texas, Discovery Park, Room No.: F101P, 1155 Union Circle #311098, Denton, TX 76207, USA ' Department of Mechanical Engineering, Clemson University, 203 Fluor Daniel Building, Clemson, South Carolina (SC) 29634, USA

Abstract: This paper presents a direct displacement synthesis method for the design of shape control of meso-structure beams with multiple V-shaped flexure springs. The objective is to design a beam that will deform to a desired final shape when under a specific load. The method uses a ground structure geometry which can facilitate variable bending stiffness along the length of the beam using compliant spring members. The synthesis procedure involves the use of direct displacement to determine how the bending stiffness of the beam must vary to produce the desired shape change. The direct displacement synthesis method differs from other compliant mechanism synthesis methods found in literature, such as pseudo-rigid-body and continuum structure optimisation, in the approach taken to solve for the unknown variables in the system. By using direct displacement to determine how the structure must respond to a specific load to achieve the desired shape change, the unknown variables within the system can be extracted directly without the use of optimisation techniques. The method is detailed and sensitivities explored. With this method and no iterations, the spring configuration values can be determined such that the resulting shape is within 1% of the target shape.

Keywords: meso-structure beams; beam flexure; shape synthesis; direct displacement; shape control; V-shaped flexure springs; bending stiffness; shape changes.

DOI: 10.1504/IJMRS.2015.069030

International Journal of Mechanisms and Robotic Systems, 2015 Vol.2 No.2, pp.144 - 168

Accepted: 06 Oct 2014
Published online: 24 Apr 2015 *

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