The main cable, which known as the primary load-bearing component of suspension bridge, is set a higher safety factor to ensure the safety generally, without regarding the secondary stress of main cables. In fact, athough the single wire of main cables is very soft, when it is bypassesed saddle or boot-heel with a small curvature radius will also give rise to bending stress. As the main cable is a flexible structure, when it is loaded vertically or horizontally and with a large deformation, will cau...