Mechanical and Acoustic Mobility of a Complex Aerospace Structure Utilizing Digital Data-Reduction Techniques

A complex aerospace structure was used to obtain experimental measurements of input and transfer impedances. The combined theoretical and experimental investigation resulted in several significant advances in the technique of impedance measurements. The utilization of an on-line analog/digital computer system for data acquisition and data analysis is considered to be the major achievement of the over-all program. Other results included the ability to relate successfully acceleration-response data obtained from a variety of sinusoidal and bandwidth-limited random-noise mechanical- and acoustic-excitation sources. This paper covers the developments leading up to the use of the analog/digital data system, the experimental procedures and results, and a discussion of the results. [Work supported by NASA-MSFC-P and VE.]