Details:

Alternative Title:
Project title: Performance and Effects of Punched Holes and Cold Bending on Steel Bridge Fabrication
Creators:
Keating, Peter B. ; Christian, Lee C.
Keating, Peter B. ; Christian, Lee C. Less -
Corporate Creators:
Texas Transportation Institute
Corporate Contributors:
Texas. Dept. of Transportation. Research and Technology Implementation Office
Subject/TRT Terms:
[+]
Bending Bolt Hole Fatigue Bolts Bridge Construction Bridge Fabrication Bridge Members Bridges Fabrication Heat-assisted Non-loaded Attachments Plate Bending Steel Plate Steel Plates
Publication/ Report Number:
FHWA/TX-10/0-4624-2
Resource Type:
Tech Report
Geographical Coverage:
Texas
Edition:
Technical report; Sept. 2003-Aug. 2006.
Corporate Publisher:
Texas Transportation Institute
Abstract:
Bridge fabricators for the Texas Department of Transportation (TxDOT) have occasionally experienced the

formation of cracks in flange plate during bending operations, particularly when heat is applied. Bending the

flange plate is necessary for certain details used in the fabrication of steel highway girders such as dapped end

details. Heat is sometimes used to assist in the bending operation, particularly to help reduce the forces required

to bend the plate. This report documents the findings of a TxDOT-sponsored research project that investigated the

possible causes of the cracking and developed recommendations to prevent the occurrence of such cracking.

The research project investigated the cracking problem using both experimental and analytical studies. The

experimental study involved the use of small tensile specimens loaded to different strain levels under varying

temperature conditions. Strain levels up to 15 percent were investigated. Temperature conditions included testing

at room temperature, 450ºF, and 1150ºF. The results showed that strain levels above 10 percent generally reduced

the ductility and fracture toughness of the plate. Additionally, it was found that the application of heat during the

bending process significantly reduced ductility and was the major contributor to the formation of cracks. A finite

element study of the heating process was used to extend the results for the experimental study.

As a secondary study, the fatigue behavior of non-loaded bolted connection details was investigated along

with the influence of plate thickness. These details occur when gusset plates are bolted to flanges of girders.

Unlike flange or web splices where the load must transfer out of the main member, the load in these details passes

through the main plate, resulting in higher stresses around the bolt holes. Pre-tensioning the bolts normally shields

the bolt holes from fatigue damage due to the resulting compressive stress field. This study found that for plate

t hicknesses greater than 1.0 inches, a reduction in fatigue strength was warranted.


Format:
PDF
Funding:
Project 0-4624
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:8468b4262bb6629b8f212647b3839caa00a0d7567dbd199b966e90194be718a5
Download URL:
https://rosap.ntl.bts.gov/view/dot/24408/dot_24408_DS1.pdf
File Type:

Supporting Files

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