Distortion of Thin-Walled Open-Cross-Section Members : For the Case of Distortion of Multi-Degree-of-Freedom

According to the one dimensional theory a thin-walled open-cross-section member is studied considering the multi-digree-of-freedom of the cross sectional distortion. Generalized equations are obtained including the conventional warping torsion theory. In these equations at number of the extended Saint-Venant's torsional constants are obtained by a definition of simple distortion. The existence of a number of distortional bimoments, corresponding rigidities and shear centers of distortion in plural is also confirmed.