The Secant Modulus of Elasticity of Stay Cables Stiffened by Secondary Steel Cables

Provided herein is the expression for calculation of the secant modulus of elasticity E^*_HS for stay cables stiffened with the application of elastic stiffening cables. The solution obtained is compared with the formulation of the tangent modulus of elasticity E_iH proposed by Tschemmernegg and Obholzer. The general validity of the formula obtained is shown, as are the significant limitations inherent in the use of the tangent expression for finite tensional ranges in the stays for purposes of comparison. It is found that vertical cables are more effective than inclined ones, although their use implies greater limitations because of fatigue phenomena and the danger of unloading.