Degree Type

Dissertation

Date of Award

2011

Degree Name

Doctor of Philosophy

Department

Mechanical Engineering

First Advisor

Judy M. Vance

Abstract

The purpose of this research is to establish a novel approach to the design of compliant shape-morphing structures using constraint-based design methods (CBDM) and virtual reality (VR). Compliant mechanisms, as opposed to rigid link mechanisms, achieve motion guidance via the compliance and deformation of the mechanism's members. They are currently being explored as structural components to produce shape changes in products such as aircraft wing and antenna reflectors. The goal is to design a single-piece flexible structure capable of morphing a given curve or profile into a target curve or profile while utilizing the minimum number of actuators.

The successful design of compliant mechanisms requires an understanding of solid mechanics (deformation, stress, strain, etc.) and mechanism kinematics (properties of motion). As a result, only a fairly narrow, experienced group of engineers are successful in designing these mechanisms. This approach was developed as an alternative to the two primary methods prevalent in the design community at this time - the pseudo-rigid body method (PRBM) and the topological synthesis (which tend to suffer from either a poor potential solution synthesis capabilities or from susceptibility to overly-complex solutions). A tiered design method that relies on kinematics, finite element analysis, and optimization in order to apply the CBDM concepts to the design and analysis of shape-morphing compliant structures is presented. By segmenting the flexible element that comprises the active shape surface at multiple points in both the initial and the target configurations and treating the resulting individual elements as rigid bodies that undergo a planar or general spatial displacement we are able to apply the traditional kinematics theory to rapidly generate sets of potential solutions. An FEA-augmented optimization sequence establishes the final compliant design candidate. Coupled with a virtual reality interface and a force-feedback device this approach provides the ability to quickly specify and evaluate multiple design problems in order to arrive at the desired solution without an excessive number of design iterations and a heavy dependence on the intermediate physical prototypes.

DOI

https://doi.org/10.31274/etd-180810-218

Copyright Owner

Denis Dorozhkin

Language

en

Date Available

2012-04-30

File Format

application/pdf

File Size

97 pages

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