The structural reliability of perforated sifting plates operating under dynamic loading conditions, including vibration, is a subject of growing scientific interest in the development of advanced material separation technologies. Although the use of perforated plates with non-standard or complex-shaped holes enhances sifting efficiency, it also introduces geometric features that may affect fatigue life and mechanical strength. This study proposes an integrated experimental–numerical methodology for predicting the service life of such perforated plates. The research involves abrasive wear testing of steel plates, characterization of loose materials (wheat, corn, granite), and finite element analysis of stress concentration zones using ABAQUS. Stress concentration factors were calculated for various critical regions of the perforated plate, considering geometric modifications, abrasive wear progression, and distributed mechanical loading. The modeling results were cross-validated with physical wear measurements obtained from real operating conditions. The methodology enables the evaluation of strength conditions and the estimation of fatigue durability under variable loading and material loss. The findings provide a basis for the optimized design, maintenance, and lifetime prediction of perforated sifting plates with complex geometries.