This book brings together the latest research on vibration fatigue and related topics from the first international event entirely dedicated to the field: a symposium held in Udine, Italy, on September 17–18, 2025, celebrating the 40th anniversary of Turan Dirlik’s doctoral thesis, which introduced the formula for the probability distribution of rainflow ranges. Featuring contributions from both academia and industry, the book covers theoretical, numerical, and experimental approaches to fatigue analysis, including spectral and probabilistic methods, non-stationary and non-Gaussian processes, shaker testing, mission synthesis, and industrial case studies. Serving as a unique reference for engineers, researchers, and practitioners, it offers cutting-edge tools and insights for the analysis, design, and testing of structures and mechanical components subjected to vibrational loads.