Resonance-induced ballistic premature detonation in fuzes: mul-ti-evidence diagnosis and assembly-based vibration suppression

This study investigates premature detonation failures in an 82 mm mortar projectile fuze using a multiscale framework combining fault tracing, time-frequency analysis, finite element simulation, and modal testing. After eliminating software, hardware, and environmental pathways through fault tree analysis, structural dynamic anomalies were identified as the primary failure mechanism. Time-frequency analysis revealed failures occurring between 34.59 and 35.17 seconds, coinciding with the turbine generator's excitation band of 1160–1240 Hz. Simulations predicted a local bending modal frequency of 1216 Hz, validated experimentally at 1204.10 Hz (0.98% deviation). The third-order mode showed high sensitivity to assembly parameters, with frequency variations reaching 271.5 Hz. A dual-side washer configuration shifted the modal frequency to 985.9 Hz and reduced response amplitudes by 56.44%. Optimized wave springs stabilized frequencies between 987.2 and 1064.6 Hz with 39.39% additional amplitude reduction. Field testing of 40 units validated the "stiffness regulation–interface dissipation" strategy.