Fatigue life evaluation and research trend in agricultural machinery: a review

Agricultural machinery is constantly exposed to repeated loads under diverse operating conditions, making fatigue life evaluation essential for ensuring structural durability. This review provides a systematic review of the literature from the last decade (2015-2025), focusing key methodologies and recent advanced in fatigue life evaluation for agricultural machinery. Relevant literature was analyzed with a focus on stress and strain data acquisition, signal preprocessing techniques, repeated load classification, mean stress correction, damage accumulation models, and FEA–MBD and DEM–MBD integrated simulation approaches. This review highlights the accuracy of in-field stress and strain measurements, the appropriateness of fatigue evaluation methods under variable mean stress, the quality of load characterization, and the feasibility of simulation-coupled fatigue analysis. Furthermore, the review presents a comparison of the applicability and effectiveness of each method based on case studies. Several limitations in current research are also identified, such as inconsistency in evaluation standards, discrepancies between experimental and simulation results, and challenges in reproducing complex operating conditions. Ultimately, this comprehensive review establishes a systematic foundation for improving structural durability evaluation, early-stage design safety, and maintenance planning for agricultural machinery.