Angle of incidence effects for underwater shock using generic computational models

The computer programs for three models which provide the ability to perform damage assessments, particularly regarding the significance of angle of incidence are described. Each computer code evaluates the temporal response of the structure for an explosive source situated at a specified angle relative to the axis. Responses are displayed as temporal histories of the velocity and acceleration components relative to a body fixed coordinate system. Such results are evaluated for the center of mass and points at each end of the cylindrical segment. When a sequence of heading angles covering a quarter circle are input, the magnitude of the instantaneous (vector) velocity and acceleration at each point is monitored for its maximum value. In conjunction with the evaluation of the structural motion, in TDEF, a simple model is used to correlate the shock severity of the structural motion to that experienced by a small piece of equipment. This model consists of a one-degree-of-freedom oscillator whose base motion is obtained from the motion arising from any of the aforementioned structural models.