Impact fatigue in adhesively bonded joints: An overlooked challenge in structural integrity

Adhesively bonded joints are increasingly employed in structural applications due to their advantages in weight reduction and efficient load transfer. However, impact fatigue represents one of the most severe and practically relevant loading conditions, as such joints are frequently subjected to repeated impacts in service. Despite its importance, the performance and failure behaviour of adhesive joints under impact fatigue loading remains poorly understood. This review examines the existing body of work on this topic (covering approximately 40 studies published between 1970 and 2026), identified through Web of Science, Scopus, and Google Scholar. While the studies vary in scope, methodology, and testing configurations, they collectively reveal a significant knowledge gap. Compared with standard fatigue, impact fatigue imposes more severe damage conditions, yet, its underlying mechanisms and design implications remain underexplored. By consolidation of the current knowledge, this review highlights critical gaps and aims to stimulate further research and industry attention toward the development of more reliable and durable design strategies for adhesively bonded joints under impact fatigue loading.