Date of Award

1991

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Civil and Environmental Engineering

First Advisor

R. Richard Avent

Abstract

A comprehensive set of experiments is conducted on damaged steel plates and rolled shapes which have been subjected to heat straightening. Effects of the repair process on the tensile properties and residual stresses in the repaired steel are experimentally determined for the first time. Based on the results, rational decisions can be made concerning the use of heat straightening and its limitations. For the first time in a laboratory setting, heavily damaged plate elements and rolled shapes are repetitively subjected to vee heat applications to produce desired straightening. Movements resulting from each heat application are recorded and provide an adequate database for modifying existing equations which have been used in the past to predict such movements for plates only. The relationship between movements in rolled shapes and plates is analytically established and experimentally verified. Results show that conclusions drawn from studies on undamaged specimens should not be assumed to apply to damaged specimens. This is especially true in the studies of residual stresses and movements resulting from vee heats on wide flange shapes. Also, tensile properties of the steel can differ from those found in undamaged plates, depending on how many times a member has been damaged and repaired using heat straightening. Other important results of the research include scientifically based suggestions regarding the use and limitations of heat straightening. These suggestions include the following topics: Degree of damage, repetitive damage, and detrimental on steel properties caused by certain heating patterns.

Pages

274

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