NEW 3-D STABILITY APPROACH FOR THE ELASTIC CABLE-STAYED TOWERS

In this book, a theoretical analysis is presented for estimating the 3-D large displacement elastic stability behavior including shear deformations of both ordinary and cable-frame interactions in their both suspended or stayed cases subjected to proportional increase in static vertical or horizontal concentrated or distributed loads or both. A new Bowing Functions has been established and checked; a new approach has been established and checked regarding the 3-D effect (SS effect). A new function called "twisting function" has been derived associated to the 3-D effect. A new tangent stiffness matrix in space including shear deformations and 3-D effect has been derived. The effect of axial force on bending, shear & torsional stiffness has been included. All other effects of temperature, lack of fit, initial imperfections, support yielding, pre- twisting members, pretension in cables & cable sag have been considered. A multi-purpose computer program (NASCFI) has been introduced. More than 30 study cases have been examined by (NASCFI) to verify its validity.