Geometry influence on warping-coupled twist actuation

Remark 10.8. The tensional stiffness Pn and the chordwise shear stiffness P22 are accepted to exhibit deviations from the application example data. 

Division of the shear stiffness coefficients of the beam, see Eq. (10.16e), by each other directly yields the cross-sectional aspect ratio 

Similarly, the bending stiffness coefficients, see Eqs. (10.16b) and (10.16c), may be divided by each other. The resulting polynomial equation has three solutions, whereof only one is real  

The results of Eqs. (10.20) and (10.21) do not agree exactly. These, as well as further discrepancies, are caused by the fact that the single-cell thin-walled box beam, naturally, is not able to represent the properties of a solid configuration with multiple materials and complicated geometry. Consequently, one or the other beam stiffness coefficient cannot be accurately matched. The prioritization of Remark 10.8 gives preference to the result of Eq. (10.21). With the values of Table B.l, the cross-sectional aspect ratio is gained  

The division of the torsional stiffness by a shear stiffness can be solved for the width h of the box beam. This can be done for each of the shear stiffness 

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