Research Of Dynamic Response In Pre-stressed Cable Bracing Steel Frame Considering Cable Rupture

With the development of the technology and times,more and more pre-stressing technologies are applied to steel structures.One of the innovative achievements for pre-stressing technology is pre-stressed cable bracing steel frame.Lateral resistance of this structure is provided by both steel frame and pre-stressed cable brace.but application of pre-stressing technology causes much strain energy in cables.The rupture of the pre-stressed cables releases large amount of strain energy in a short period of time,which causes dynamic effects on the structure.In order to study the dynamic response of remaining structure caused by cables' rupture in pre-stressed cable bracing steel frame,and analyze the effect of different parameters(cable initial stress,cable diameters,and so on)on the dynamic response of remaining structures,three typical kind of steel frame-pre-stressed structures are investigated.The analysis is based on the dynamic module of SAP2000 software,and the cables' rupture is simulated by alternate path method.The analyzing models are pre-stressed cable bracing single-story steel frame,pre-stressed cable bracing multi-story steel frame and pre-stressed cable bracing mega steel frame.Results are as follows:(1)In pre-stressed cable bracing single-story steel frame,the best cable-breaking time is less than 0.1T1(T1 represents the structural natural period of vibration).The best cable-breaking way can be demonstrated as linear step function.The stronger the damping is,the weaker the dynamic response of the remaining structure is.The larger the cables' pre-stress is,the stronger the dynamic response of the remaining structure is.In common conditions,the dynamic response of the remaining structure becomes stronger with the decreasing of the cable's diameters.But when coupling of transverse and vertical vibration mode occurs,dynamic response becomes much stronger.(2)For pre-stressed cable bracing multi-story steel frame,the larger the cable force is,the stronger the dynamic response is.With the increasing of the cables' diameters and span,changing tendency of dynamic response of different parts for remaining structures is different.(3)For pre-stressed cable bracing mega steel frame,with the increasing of cables' pre-stress and diameters,changing tendency of dynamic response of different parts for remaining structures is different.