Evaluation of flight equipment acceleration caused by random vibration loads

The current approach to the evaluation during the preliminary design phase of random vibration loads acting on flight equipment is based on the use of Miles's equation, assuming the component as a single-degree-of-freedom sys tem subjected to white noise excitation; usually this technique provides to o many conservative results with respect to actual accelerations recorded d uring the flight. In contrast, an accurate evaluation of equipment accelera tion can be obtained by running a complete random vibration analysis throug h a finite element program, e-g., NASTRAN, but because this approch is extr emely time comsuming it cannot be applied during the design cycle. The aim here is to describe an accurate and cost-efficient procedure to evaluate th e acceleration of components installed on aerospace structures subjected to random vibrations. Several numerical examples and comparisons with results obtained with NASTRAN complete the work.