Target Description Data For The M113 Armored Personnel Carrier

An experimental comparative modal analysis was performed on a standard Ml 13 armored personnel carrier and an experimental Ml 13 armored personnel carrier. The objective of this experiment was to provide sufficient experimental data to validate survivability finite element models and to extract modeling parameters and information wherever appropriate. This report details the results of the analysis performed on the data provided by the University of Cincinnati Structural Dynamics Research Laboratory. Each hull was tested in two configurations: a basic configuration consisting of the stripped hull, and a "tight-fitting" configuration consisting of the basic hull configuration to which dynamically linear behaving components, such as the engine, hatches, and doors, were attached to approximate a full-up vehicle. The first elastic mode of the basic metallic hull was observed at 43.3 Hz (0.21% critical damping) while the first elastic mode of the basic composite hull was observed at 27.5 Hz (1.3% critical damping). Numerous local modes of varying degrees of complexity were observed for the tight-fitting configurations. This report describes the characteristics and peculiarities of all observed modes.