Doctoral Dissertations

Keywords and Phrases

Compliant Mechanisms; Creep; Fatigue; Pseudo-Rigid-Body Model; Stress Relaxation

Abstract

"A methodology is developed for analyzing stress within homogeneous and metallic-reinforced, fixed-free compliant segments and small-length flexural pivots. Boundary conditions related to the inclusion of metallic reinforcing components within a polymer compliant segment are investigated. The analysis method outlined herein relies on key outputs from the pseudo-rigid-body models (PRBMs). A method is presented for the redesign of compliant mechanisms to include metallic reinforcement to reduce stress while maintaining force-deflection behavior. Examples are provided in which a compliant segment is redesigned to include metallic reinforcement by using the stress equations developed from the PRBM. The effect of bonding between the polymer casing and the metallic reinforcement is addressed by presenting theoretical calculations as well as results obtained from deflection testing of compliant segments with near-frictionless tangential behavior and by testing segments with an intentional bond between the casing and insert. Fatigue, creep, and stress relaxation test results are presented to show the improvement in performance provided by the inclusion of metallic reinforcement. Lastly, fractography provides an overall view of the fracture behavior, including fracture initiation sites and propagation behavior of both homogeneous and metallic-reinforced compliant segments. The results show that the fatigue, creep and stress relaxation behavior of a compliant segment can be significantly improved by redesigning the segment to include a metallic reinforcing member"--Abstract, page iv.

Advisor(s)

Dharani, Lokeswarappa R.
Midha, A. (Ashok)

Committee Member(s)

Birman, V. (Victor)
Chandrashekhara, K.
Thomas, Jeffery S., 1971-

Department(s)

Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2016

Journal article titles appearing in thesis/dissertation

  • Stress analysis of a fixed-free compliant segment using the pseudo-rigid-body model (PRBM) concept
  • Stress analysis of a small-length flexural pivot compliant segment using the pseudo-rigid-body model (PRBM)
  • Reduction of stress in plastic compliant mechanisms by introducing metallic reinforcement
  • Creep and stress relaxation behavior of homogeneous and reinforced compliant mechanisms and segments
  • Fatigue and failure behavior of homogeneous and reinforced compliant mechanism segments

Pagination

xiv, 198 pages

Note about bibliography

Includes bibliographic references.

Rights

© Joshua Allen Crews

Document Type

Dissertation - Open Access

File Type

text

Language

English

Library of Congress Subject Headings

Mechanical movements -- Research
Dynamics, Rigid -- Research
Strains and stresses
Materials -- Fatigue -- Analysis
Materials -- Creep -- Analysis

Thesis Number

T 11064

Electronic OCLC #

974710050

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