U.S. Department of Transportation
Federal Highway Administration
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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
REPORT |
This report is an archived publication and may contain dated technical, contact, and link information |
Publication Number: FHWA-HRT-20-056 Date: August 2020 |
Publication Number: FHWA-HRT-20-056 Date: August 2020 |
PDF Version (20 MB)
This report documents fatigue and tensile test results of steel plates with round holes fabricated using plasma arc cutting. Bridge owners, designers, and fabricators have shown interest in using plasma arc cutting as a more economical alternative to traditional hole fabrication methods. However, a lack of experimental data demonstrating the behavior of plasma-cut holes under fatigue and tensile loading has hindered their use in steel bridge design and fabrication. FHWA initiated this study to categorize the fatigue and static tension resistance of plasma-cut holes in steel bridge members. This research establishes the design fatigue resistance and assesses the fracture behavior of steel members with plasma-cut holes. Multiple plasma-cutting processes were evaluated. Results showed that fatigue resistance of plasma-cut holes is lower compared to current hole-making methods. Tensile testing showed that certain plasma-cutting processes could cause brittle failure modes in tension members with plasma-cut holes.
This report will benefit those interested in the design and fabrication of round holes in steel bridge members, including State departments of transportation, bridge design consultants, bridge owners, steel bridge fabricators, and researchers.
Cheryl Allen Richter, P.E., Ph.D.
Director, Office of Infrastructure
Research and Development
Notice
This document is disseminated under the sponsorship of the U.S. Department of Transportation (USDOT) in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document.
The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear in this report only because they are considered essential to the objective of the document.
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Technical Report Documentation Page
1. Report No.
FHWA-HRT-20-056 |
2. Government Accession No. | 3. Recipient's Catalog No. | ||
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4. Title and Subtitle
Evaluation of Holes Fabricated Using Plasma Arc Cutting |
5. Report Date
August 2020 |
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6. Performing Organization Code | ||||
7. Author(s)
Christopher Beckett, Ph.D., P.E., and Justin Ocel, Ph.D., P.E. (ORCID 0000-0002-0176-7276) |
8. Performing Organization Report No. | |||
9. Performing Organization Name and Address
Professional Service Industries, Inc. |
10. Work Unit No. (TRAIS) | |||
11. Contract or Grant No.
DTFH61-10-D-00017 |
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12. Sponsoring Agency Name and Address
Office of Infrastructure Research and Development |
13. Type of Report and Period Covered
Final Report; June 2012–October 2016 |
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14. Sponsoring Agency Code
HRDI-40 |
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15. Supplementary Notes
The work reported herein was conducted under Federal Highway Administration contract support services for the structures laboratories. Justin Ocel, Ph.D. (HRDI-40), provided technical oversight/assistance as the Task Manager and wrote portions of the report. Fassil Beshah, Ph.D. (HRDI-40), served as the Contracting Officer's Representative of this contract. |
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16. Abstract
Modern plasma-cutting equipment and techniques can produce high-quality holes more economically than drilling and punching. However, American Association of State Highway and Transportation Officials (AASHTO) design and construction specifications do not permit the use of plasma-cut holes in primary bridge members due to a lack of experimental data demonstrating their fatigue and tensile strength. Additionally, it is uncertain if holes fabricated using plasma arc cutting meet the AASHTO requirements for hole size accuracy. This research shows that round open holes fabricated using plasma arc cutting would be an AASHTO category E fatigue detail. Bearing connections with nonpretensioned bolts installed in plasma-cut holes would be classified as category E′. Both results represent lower fatigue resistance compared to drilled or punched holes. Most tension members produced a tensile strength equal to or exceeding the theoretical nominal tensile strength. However, several tension members did not attain the theoretical nominal strength and a reduction factor was necessary when calculating the tensile resistance of a member with plasma-cut holes. Tension testing at low temperatures revealed that members with conventional plasma-cut holes can fail with brittle fracture and insignificant inelastic deformation. Lastly, the four fabricators used for this study provided a mostly consistent hole diameter over numerous samples. However, variation in diameter was large enough that close quality control was required. |
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17. Key Words
Steel bridge, plasma arc cutting, bridge fabrication, hole-making, fatigue |
18. Distribution Statement
No restrictions. This document is available through the National Technical Information Service, Springfield, VA 22161. |
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19. Security Classification (of this report) Unclassified |
20. Security Classification (of this page) Unclassified |
21. No. of Pages
159 |
22. Price
N/A |
Form DOT F 1700.7 (8-72) | Reproduction of completed page authorized |
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