Title page for ETD etd-520112859651791

Type of Document

Master's Thesis

Author

Waldhart, Chris

URN

etd-520112859651791

Title

Analysis of Tow-Placed, Variable-Stiffness Laminates

Degree

Master of Science

Department

Engineering Science and Mechanics

Advisory Committee

Advisor Name	Title
Zafer Gurdal	Committee Chair
Calvin Ribbens	none
Robert M. Jones	none

Keywords

variable-stiffness laminates
curvilinear fibers
tow placement machine
buckling

Date of Defense

1996-06-05

Availability

unrestricted

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.

Files

Filename		Size	Approximate Download Time (Hours:Minutes:Seconds)
Filename		Size	28.8 Modem	56K Modem	ISDN (64 Kb)	ISDN (128 Kb)	Higher-speed Access
	cwaldhar.pdf	2.01 Mb	00:09:19	00:04:47	00:04:11	00:02:05	00:00:10
	etd.pdf	2.01 Mb	00:09:19	00:04:47	00:04:11	00:02:05	00:00:10