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Virginia Tech

Analysis of Tow-Placed, Variable-Stiffness Laminates

Abstract

dc:description.abstract

It is possible to create laminae that have spatially varying fiber orientation with a tow placement machine. A laminate which is composed of such plies will have stiffness properties which vary as a function of position. Previous work had modelled such variable-stiffness laminae by taking a reference fiber path and creating subsequent paths by shifting the reference path. This thesis introduces a method where subsequent paths are truly parallel to the reference fiber path. The primary manufacturing constraint considered in the analysis of variable-stiffness laminates was limits on fiber curvature which proved to be more restrictive for parallel fiber laminae than for shifted fiber. The in-plane responses of shifted and parallel fiber variable-stiffness laminates to either an applied uniform end shortening or in-plane shear were determined. Both shifted and parallel fiber variable-stiffness laminates can redistribute the applied load thereby increasing critical buckling loads compared to traditional straight fiber laminates. The primary differences between the two methods is that parallel fiber laminates are not able to redistribute the loading to the degree of the shifted fiber. This significantly reduces the increase in critical buckling load for parallel fiber variable-stiffness laminates over straight fiber laminates.

Degree

thesis:*
Name thesis:degree_name
Master of Science
Level thesis:degree_level
masters
Discipline thesis:degree_discipline
Engineering Science and Mechanics
Department dc:contributor.department
Engineering Science and Mechanics
Grantor dc:publisher
Virginia Tech
Year dc:date.issued
1996

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Waldhart, Chris
Chair dc:contributor.committeechair
  • Gürdal, Zafer
Committee members dc:contributor.committeemember
  • Jones, Robert M.
  • Ribbens, Calvin J.

Subjects

dc:subject × 4

Rights

dc:rights
Statement dc:rights
  • In Copyright

Identifiers

dc:identifier.*
Dc Identifier Other
etd-520112859651791
OAI identifier oai:identifier
oai:vtechworks.lib.vt.edu:10919/36781

Chain of custody

source
Harvested from
Virginia Tech
Base URL
vtechworks.lib.vt.edu/oai/request
Last updated
2026-07-22
Source record
OAI-PMH GetRecord
citation

Waldhart, Chris. Analysis of Tow-Placed, Variable-Stiffness Laminates. masters thesis, Virginia Tech, 1996. http://hdl.handle.net/10919/36781