Dynamic Analysis of a Tactical Rigid Shelter Subjected to Rail Impact

Abstract : In this effort a technical database was developed for a Tactical Shelter experiencing rail impact. A finite element model of the shelter and internal equipment was made, a test was conducted in which accelerations were measured on the shelter, the flatcar, and on the internal equipment during rails impact. The measured accelerations on the flatcar were used to determine the spectra of the dynamic loads acting on the shelter and the response of the shelter to forced acceleration impulses in the frequency range of the measured data was determined. We found that the shelter's lowest structural vibration modes, as predicted by the finite element model, were in the range of the frequencies in the power spectral density representation of the rail car response. The shelter responded almost rigidly in the longitudinal direction but did vibrate in the vertical and transverse directions. Computed mode shapes, measured accelerations, analysis of the data and the predicted response of the shelter to impulse loadings are presented in the report. Keywords: ISO shelters; Finite element analysis; Army shelters; Dynamic analysis; Freight containers.