Load spectrum editing for automotive fasteners based on bolt critical load

The durability of threaded fasteners is critical to chassis reliability. Conventional load spectrum editing often retains low-amplitude, high-cycle loads that extend test time without affecting preload. This study introduces an accelerated editing method that integrates the bolt critical load threshold with the S-transform to account for the loosening mechanism of fasteners. Road load data were collected under representative driving conditions, and the proposed method was used to remove non-damaging segments while preserving fatigue-relevant features. Simulation results show that the edited spectrum significantly shortens test duration while maintaining consistency with the original in statistical parameters, spectral distribution, and fatigue damage. The method improves testing efficiency and provides practical value for automotive durability evaluation, product development, and quality assurance.