Title page for ETD etd-211714251972550

Type of Document

Dissertation

Author

Warren Jr., J.E.

URN

etd-211714251972550

Title

NONLINEAR STABILITY ANALYSIS OF FRAME-TYPE STRUCTURES WITH RANDOM GEOMETRIC IMPERFECTIONS USING A TOTAL-LAGRANGIAN FINITE ELEMENT FORMULATION

Degree

PhD

Department

Engineering Science and Mechanics

Advisory Committee

Advisor Name	Title
S. Thangjitham	Committee Chair
D. H. Morris	none
D. T. Mook	none
R. H. Plaut	none
S. M. Holzer	none

Keywords

Reliability
Imperfection
Stability
Finite Element
Nonlinear

Date of Defense

1998-07-12

Availability

unrestricted

Abstract

With the increasing use of lightweight frame-type structures that span long distances, there is a need for a

method to determine the probability that a structure having random initial geometric imperfections will

become unstable at a load less than a spe cified fraction of the perfect critical load. The overall objective of

this dissertation is to present such a method for frame-type structures that become unstable at limit points.

The overall objective may be broken into three parts. The first part co ncerns the development of a

three-dimensional total Lagrangian beam finite element that is used to determine the critical load for the

structure. The second part deals with a least squares method for modeling the random initial imperfections

using the mo de shapes from a linear buckling analysis, and a specified maximum allowable magnitude for the

imperfection at any imperfect node in the structure. The third part deals with the calculation of the

probability of failure using a combined response surface/ first-order second-moment method. Numerical

results are presented for two example problems, and indicate that the proposed method is reasonably

accurate. Several problems with the proposed method were noted during the course of this work and are

discuss ed in the final chapter.

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
	etd.pdf	1.35 Mb	00:06:15	00:03:12	00:02:48	00:01:24	00:00:07
	ETDB.PDF	1.35 Mb	00:06:15	00:03:12	00:02:48	00:01:24	00:00:07