A need exists within the Army to model and predict the response of combat vehicles to high-frequency, high-energy, nonpenetrating impacts. Statistical energy analysis (SEA) based models are one possible solution to this task. However, data must be obtained to characterize the modeled materials as well as to validate the modeling tool. A technique was developed at the U.S. Army Research Laboratory for producing and directly measuring impacts with a peak force level of 30,000 lb and a frequency content of up to 10,000 Hz. The frequency response as well as the peak force of this new impact technique can be tailored to meet specified levels while still permitting direct measurement of the force input. Although the technique utilizes a powder-actuated tool, minimal additional safety precautions are necessary. The high-frequency energy available using this excitation technique permits validation of the predictive modeling tool on a case-by-case, deterministic basis for ballistic-shock-level excitation. Due to the ability to directly measure the excitation and thus calculate transfer functions, this method is also ideally suited for obtaining modal measurements when a high force/frequency impulsive excitation is desired. This paper describes the excitation methodology as well as a case history in which the methodology is applied to a partial composite armored vehicle hull. The SEA model used is discussed briefly as well as the material characterization (damping and modal density) work that supported the SEA model.
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