Analysis of axial vibration frequency for projectile structure in penetration

In the measurement of a projectile's acceleration history using an acceleration transducer, the results achieved contain the acceleration resulting from the hindrance of a target that decelerates the projectile and the acceleration resulting from the structural vibration of the missile. In this study, a simple model was established simplifying the projectile as a long straight round bar and analyses the frequency characteristics of the axial vibration of a projectile. A finite element model of the projectile was built using ANSYS to solve the natural frequency and mode of the projectile via modal analysis, then the harmonic response analysis about the projectile was conducted. The theoretical results and simulated results were quite consistent, both about 1 200 Hz. The frequency characteristics of the actual acceleration signal obtained from the target experiment were analyzed via the Fourier transform and wavelet analysis. The peak value of the signal power density spectrum was at 1 114 Hz, consistent with both the theoretical value and the simulated result.