Optimization Design Analysis Of Key Components Of Flexible Suspension Bridge Based On Damage Safety

In Southwest China,the mountains are overlapped and ravines are crisscross,most of which are high mountains and canyons.Its geological features determine the importance of flexible suspension bridges in mountain bridges.Although a certain safety factor is considered in the design of flexible suspension bridge,there are many uncertain factors(such as large overload,fatigue,corrosion,etc.) in service,which will lead to its damage and threaten the safe operation of the structure.In this paper,taking the Chelige bridge as an example,based on the damage safety theory,the optimization design measures of cable clamp safety cable,damaged safety suspender based on poor life,and wind cable system are proposed,and the stress analysis and research are carried out.(1)This paper introduces the advantages,forces and development history of the flexible suspension bridge,then expounds the structural optimization design and the damage safety theory in detail,and puts forward the optimal design scheme for the cable clamp,suspender and wind resistance performance of the flexible suspension bridge.(2)Based on the theory of damage safety,the optimization method of setting safety cable between two cable clamps is put forward,which can monitor the situation of cable clamps in real time and provide additional anti sliding force for cable clamps.The calculation method of safety cable is summarized and the modified formula of minimum breaking force is put forward.Finally,the parameters of safety cable are analyzed.(3)The single suspender is optimized to be a single suspender system composed of internal and external parts based on strength difference and stress difference,and the above scheme can not achieve its life difference through comparative analysis.Therefore,the method of setting elastic block under s beam is proposed to achieve its stress amplitude difference,and the whole dynamic simulation method is used to simulate the sudden fracture of suspender,and the dynamic response is closer to the static result with the increase of elastic block stiffness.Finally,by changing the arearatio and stiffness ratio of F and s bundles,the best parameters of the safety suspender with poor life are studied.(4)Based on the analysis of the dynamic characteristics of different types of wind resistant cables,it is concluded that V-type wind resistant cables have the best wind resistant performance.Based on the optimization of angle and cross-sectional area parameters,it is concluded that 45 ° angle wind resistant cables are the best scheme,and the applicable range of cross-sectional area is 0.75 A ? A.In view of the main cable fracture caused by the disaster of Yansai lake,it is proposed that the bearing capacity of upstream and downstream wind resistant cables are different,and the anchorage treatment and the combination of the two measures optimize the wind resistance performance of the suspension bridge.