A Multi-Layer Progressive Analysis Method for Collision Energy Flow in Rail Trains

• A novel multi-layer progressive analysis method decomposes train collision energy flow into conversion, dissipation, and transfer layers, enabling systematic understanding of energy distribution. • Power flow theory-based modeling reveals that collision energy decays by 79% along the train operation direction, highlighting the dominant role of energy dissipation in the front structures. • The study identifies that even when mean acceleration meets standards, jerk can exceed human tolerance, posing secondary collision injury risks—critical for occupant safety design. • Energy convergence in perforated structures leads to localized deformation when accumulated energy exceeds structural capacity, guiding crashworthiness optimization.