A Modeling of a New Store Installed in Fighter Aircraft 2005-01-2384
The installation of a new store in an aircraft introduces changes to its structural dynamics characteristics. Such new configuration can present undesirable instabilities in flight. One of the most dangerous instabilities that the aircraft may experience is flutter. It is a disastrous interaction among inertial, elastic and aerodynamic forces present in the modified aircraft configuration. Therefore, this phenomenon must be prevented.
In the study of flutter, the knowledge of parameters such as natural frequencies, damping and shapes of some vibration modes of the aircraft-store/suspension assembly is of crucial importance. These parameters can be obtained from ground vibration tests.
This work presents a set of ground vibration test results of a new store intended to be installed in a fighter aircraft. The results are the natural frequencies, damping and mode shapes and are used to evaluate a three-degree-of-freedom model that will represent the mechanical system. The methods to obtain the inertia and stiffness parameters will be analyzed carefully in this paper.