Finite element analysis of 3-dimensional large rotation problem of a beam has been possible by means of nonlinear beam model by J. C. Simo and L. Vu-Quoc. Their beam model is regarded as geometrically exact, and described by a configulation manifold which involves the rotation group. In result, the tangent stiffness matrix becomes non-symmetric away from equilibrium. But the author showed that the tangent stiffness of semitangential rotation ΔδΠs became symmetric and by the analysis of fundamental problems it was proved that symmetric tangent stiffness was valid. By the way, the beam model is assumed large rotation and small strain. In this report, I will show the geometric stiffness of large strain by the variation of deformation gradiant tensor before rigid body rotation. This formulation is total lagrangian formulation.
A low-cost, RPRV (Remotely-Piloted Research Vehicle) flight experiment system for the study of the aerodynamic characteristics of airplanes has been developed. The cost has been kept to a minimum by utilizing devices and techniques of radio-controlled models. Severe limitations on size and weight have to be met by all airborne components. On the ground, computerized data processing and test-sequence handling have been necessary. It has been necessary to select appropriate sensors, especially for the airdata sensors working in very low dynamic pressures, and to make careful calibrations both in the laboratory and on the field. Attentions have been paid to keep errors of the measured data within 1% of maximum variation to enable meaningful comparison with other measurements and calculations.