NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Jeffrey W. Sowards, Erik A. Pfeif, Matthew J. Connolly, Joseph D. McColskey, Stephanie L. Miller, Brian J. Simonds, James R. Fekete
Abstract
Incorporation of high-strength steels into ground vehicles provides a weight-savings advantage by using thinner sections of material, which increases vehicle efficiency. Advanced welding techniques such as fiber laser welding are a potential method for joining the high-strength steels that can greatly increase productivity. However, weld fatigue is also a primary design consideration for implementation of laser-welded sheet. Much of the previous fatigue work on fiber laser welded sheet steel has focused on stress-controlled fatigue testing. Therefore, this paper presents an optimized fiber laser welding procedure for butt welds of high-strength low-alloy steel sheet, and subsequent fully-reversed, strain-controlled low-cycle fatigue testing on weld material. Existing low cycle fatigue models adequately describe fatigue behavior of the laser welds. The results show that weld low cycle fatigue strength is significantly increased relative to base metal due to formation of martensite in the weld caused by rapid cooling inherent to laser welding. Weld fatigue life was shorter than base metal when plastic strains were high, but were close to base metal at lower plastic strains. Fatigue specimens containing weld failed at both base metal and in the weld indicating that there is some competition between weld cyclic fatigue strength and stress concentration effect at the weld fusion zone.
Sowards, J.
, Pfeif, E.
, Connolly, M.
, McColskey, J.
, Miller, S.
, Simonds, B.
and Fekete, J.
(2017),
Low-Cycle Fatigue Behavior of Fiber-Laser Welded, Corrosion-Resistant, High-Strength Low Alloy Sheet Steel, Materials and Design, [online], https://doi.org/10.1016/j.matdes.2017.02.065
(Accessed October 11, 2025)