INCREASED RELIABILITY OF AVIATION AND MISSILE ELECTRONICS BY USE OF DAMPED STRUCTURES 590360
Prior to the introduction of high speed aircraft, conventional methods of constructing support structures, electronic equipment chassis and electronic or mechanical components were acceptable. Relatively low frequencies were of interest and equipment of standard design could be adequately protected from vibration and shock by judicious use of vibration and shock isolation systems. However, due to the extreme vibrational environments associated with high speed vehicles, there is currently an increased interest in the high frequency response of equipment. Elastic body resonances have now become perhaps the prime cause of low component reliability and life. These resonances are of major importance since it is required that the equipment operate properly over a wide frequency range. Many of the resonant conditions that exist in the structures comprising the system will be included in this frequency range. Transmitted accelerations are amplified to extremely high values at these resonant frequencies producing large dynamic loads which damage the equipment. In order to increase the reliability and life of such equipment, the resonant amplification problem must be overcome. This is accomplished by the design of structures and equipments with extremely high damping properties. This paper deals with the control of elastic body resonances by use of damped structures. Several idealized models of the problem are analyzed, constructed and tested to indicate the beneficial properties of highly damped structures. The effect of high structural damping on the isolation of vibration is also studied.