Proceedings of the Shock and Vibration Symposium (62nd) Held in Springfield, Virginia on October 29 -31, 1991. Volume 2
Abstract
This paper reports on the degree of success that may be achieved by using simple equipment-vehicle models that produce time history responses which are equivalent to the responses that would be achieved using spectral design values employed by the Dynamic Design Analysis Method. The equipment models studied herein are limited to one and two-degree of freedom systems; the vehicle to which the equipment is attached consists solely of a rigid mass; and the shock excitation is produced by an ideal impulse that is applied to the vehicle mass so as to produce an initial velocity. Although the case of the single-degree of freedom equipment presents no difficulties in performing a transient analysis that reproduces the DDAM-like response, it is shown that there are no unique values for the vehicle mass and for the magnitude of the impulse, but that they are interrelated. In the case of the two-degree of freedom equipment, the transient analysis duplicates the response that would be experienced using the DDAM-like input values, provided the shock design value in the first mode is less than the shock design value in the second mode. Otherwise, solutions are not possible. Brief comments are also provided for the special case of an equipment composed of a very light mass attached to a large mass, and for the case of an equipment with repeated natural frequencies.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 31, 1991
- Accession Number
- ADA249267