Topics On Flexible Airplane Dynamics The Application Of Flexible Airframe Transfer Function Approximations And The Sensitivity Of Airframe Transfer Functions To Elastic Mode Shapes PDF Download

The generality of the airframe transfer function factor approximation formulas presented in ASD TDR-279 is tested by applying them to three dif ferent aircraft. The equations of motion for the test cases are presented and the exact and approximat1actors have been tabulated. The approximation formulas are then utilized to cal culate the sensitivity of the flexible airframe transfer function factors to mode shape. The formulas are given in terms of airplane stability derivatives which in turn are functions of the elastic mode deflections. Then, using the re sults of ASD-TDR-62-279, the desired sensitivity is readily calculable. Many of the transfer function factors are shown to be relatively in sensitive to mode shape, thus allowing effective approximation. A review of the literature per taining to approximate methods for calculating elastic mode shapes is presented in the form of an annotated bibliography. (Author).