Alleviating Capabilities of the Sailplane Structure

Abstract

One of the most important requirements in sailplane design is to reduce the structure mass as far as possible.  The dimensions of the elements, especially the mass, of the primary structure depend on the loads calculated for all the critical flight and ground conditions.  The results of the loading calculations for the sailplane considered as an elastic body are discussed and compared with these obtained for the corresponding rigid body.  When the elasticity of the sailplane is taken into account there is some alleviation of the loads at critical conditions.  The distortion of the structure changing the incidence of the control surfaces or absorbing a portion of the energy results in a decrement of the load values.  In particular, the maneuvering loads on the control surfaces are considerably alleviated as a result of the elasticity of the control circuit elements.  Such an investigation, thus, permits some reduction in the mass of the sailplane.