Role Of End-Fitting On The Fundamental Bending Mode Frequency Of A Structural Support Bracket

In many occasions, a small object like a sensor is placed at a distance from the spacecraft body by using a long bracket. Such brackets have small end fittings to facilitate its mounting on to the spacecraft body. One of the important considerations for the design of such brackets is the need of having the fundamental bending mode frequency to be more than certain specified value. As the end fitting is short and considered to be stiff, the natural frequency is calculated without considering the end fitting. Through several experimental and theoretical investigations, it is shown here that the fundamental bending mode frequency of such support bracket is very much influenced by the stiffness of the end fitting. The end fitting acts like a rotational spring. The rotational stiffness of this specific end fitting is also determined.

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