Research progress and prospect of laser shock peening technology in aircraft structure

Light alloys such as aluminum alloy and titanium alloy are widely used in load-bearing structures such as aircraft beams，frames and panels. Since critical problems such as stress concentration and high working stress exist in the local areas such as holes，grooves，sockets and joints of aircraft，fatigue cracks are easy to occur under alternating load during service，restricting the service life of aircraft structures and even affecting flight safety. As a novel surface plastic-strengthening technology，Laser Shock Peening （LSP） can significantly improve the fatigue performance by imparting compressive residual stress and improving microstructure in the surface layer of the material without changing the material and structure size. Engineering applications of LSP have been realized in the U. S. F-22，F-35 and other aircraft. In this paper，the research progress and unsolved problems in LSP of typical aircraft structures including holes，welding，chamfers and high-bearing regions are deeply discussed. Besides，the research history and development characteristics of LSP of aircraft structures in recent years are analyzed and summarized. Moreover，research prospects are made from the aspects of equipment，mechanism，process and engineering application. By systematically teasing the research progress and technical problems，this paper aims to clarify the theoretical support and key technology required for future engineering application，facilitate the rapid development and collaboration of related innovation and industrial chains，and promote the large-scale application of LSP technology in anti-fatigue manufacturing and life-extension repairing of aircraft structures in China. © 2023 AAAS Press of Chinese Society of Aeronautics and Astronautics. All rights reserved.