EFFECTS OF GEOMETRICAL ASYMMETRIES OF STRUCTURE ON DYNAMICAL CHARACTERISTICS OF 2 COUPLED CONTROL SURFACES

The dynamical characteristics of two coupled control surfaces with str uctural asymmetries are studied. The results show that a first order a nd a second order perturbation method can be applied to predict free v ibration frequencies and modal shapes accurately. If the stiffness val ue of the operational system (or asymmetrical degree) is large enough, a small asymmetrical parameter can lead to the vibration isolation of one control surface, which means that the vibrating amplitudes of one control surface are large, but those of the other control surface are close to zero. In order to avoid such vibration isolation of control surfaces, the operation stiffness (or the asymmetrical degree) must be decreased as far as possible in the structural designs of two coupled control surfaces. (C) 1997 Academic Press Limited.