An Approach to the Problem of Estimating Severe and Repeated Gust Loads for Missile Operations

An analysis of available airplane measurements of vertical gust velocity is presented in order to arrive at a simple description of the frequency and intensity of gust velocities experienced by airplanes in operations. For the purpose of application to missile operations; the results obtained are modified to eliminate the effects of storm-avoidance procedures normally followed in airplane operations. The frequency distributions of gust velocity are then converted to a form appropriate for use in power spectral response calculations. Methods of applying the results to the estimation of the large and the small repeated loads in missile operations are then developed. Simple methods of estimating the gust loadings that will be exceeded with a given probability are presented in terms of missile response parameters and turbulence parameters. The limitations of the present results are also discussed briefly.