Title page for ETD etd-112999-093701

Type of Document

Master's Thesis

Author

Farmer, Anthony Lee

Author's Email Address

afarmer@vt.edu

URN

etd-112999-093701

Title

Investigation Into Snap Loading of Cables Used in Moored Breakwaters

Degree

Master of Science

Department

Civil Engineering

Advisory Committee

Advisor Name	Title
Plaut, Raymond H.	Committee Chair
Holzer, Siegfried M.	Committee Member
Rojiani, Kamal B.	Committee Member

Keywords

nonlinear dynamics
vibration
snap loading
breakwater
mooring lines

Date of Defense

1999-11-18

Availability

unrestricted

Abstract

A two-dimensional, nonlinear dynamic analysis is conducted on a moored breakwater
configuration to investigate snap loads in mooring lines. Breakwaters are structures used
to attenuate or eliminate waves and protect shorelines, harbors, and other natural and
man-made marine structures from wave damage. The breakwater in this investigation is
modeled both as a point mass and as a rigid body. Both models are subjected to free
undamped motions and forced undamped wave motion. Energy is dissipated through the
use of a coefficient of restitution applied when a mooring line becomes taut (i.e., reaches
its natural length). The mooring line is modeled as an inextensible cable with no axial or
bending resistance when slack. Snap loading arises when a mooring line transitions
suddenly from a slack condition to a taut condition. The analysis was conducted on a
breakwater configured upside down and hanging by two mooring lines. The length of the
mooring lines, coefficient of restitution, size and shape of the breakwater, initial position
of the breakwater, amplitude of wave forcing, ratio of vertical to horizontal forcing, and
frequency of forcing were all varied in the analysis. The results show that the rotations of
the rigid body and the wave forcing have a significant role in the analysis, indicating that
a rigid-body model for a moored breakwater under wave forcing is the more accurate model.

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Filename		Size	28.8 Modem	56K Modem	ISDN (64 Kb)	ISDN (128 Kb)	Higher-speed Access
	Chapter1.pdf	59.65 Kb	00:00:16	00:00:08	00:00:07	00:00:03	< 00:00:01
	Chapter2.pdf	73.93 Kb	00:00:20	00:00:10	00:00:09	00:00:04	< 00:00:01
	Chapter3.pdf	149.74 Kb	00:00:41	00:00:21	00:00:18	00:00:09	< 00:00:01
	Chapter4.pdf	479.81 Kb	00:02:13	00:01:08	00:00:59	00:00:29	00:00:02
	Chapter5.pdf	213.21 Kb	00:00:59	00:00:30	00:00:26	00:00:13	00:00:01
	Chapter6.pdf	454.37 Kb	00:02:06	00:01:04	00:00:56	00:00:28	00:00:02
	Chapter7.pdf	37.20 Kb	00:00:10	00:00:05	00:00:04	00:00:02	< 00:00:01
	Introduction.pdf	50.10 Kb	00:00:13	00:00:07	00:00:06	00:00:03	< 00:00:01
	References.pdf	82.16 Kb	00:00:22	00:00:11	00:00:10	00:00:05	< 00:00:01