Analysis Of Mechanical Characteristics Of Pedestrian Suspension Bridge In Mountain Area

A large number of pedestrian suspension bridges will be built in mountainous areas,cities and scenic spots.Compared with long-span highway suspension bridges,pedestrian suspension bridges have smaller span and different loads,It is of great significance to study pedestrian suspension bridges in mountainous areas.This paper first introduces the characteristics of suspension bridges,briefly describes the development of domestic and foreign,and introduces the current situation and characteristics of pedestrian suspension bridges,pointing out the significance of pedestrian suspension bridges;briefly describes the calculation theory and development process of suspension bridges,and the application of finite element method are briefly described.Then the dynamic equation of the structure system is deduced by using the dynamic principle,and the method of solving the structure frequency and vibration mode by the finite element method is briefly expounded.Taking Tian ba tao River Pedestrian Suspension Bridge as the research background,a spatial finite element model is established by using the finite element analysis software MIDAS.The structural stress responses of different components under self-weight,crowd load,wind load,combination of self-weight and wind load,and combination of self-weight and crowd load are analyzed.The internal forces,stresses and displacements under loads and load combinations are analyzed,and the frequency and mode of vibration are obtained.Then,by changing the constraints of cable-pylons,pylons,longitudinal beams and main cables,the influence of related factors on the static and dynamic characteristics of the structure are studied.It is concluded that the bridge is most likely to produce vertical vibration and torsional vibration of the deck system,and the bridge has a strong lateral connection,two adjacent vibration modes may be excited at the same time in some frequency range;suspenders can connect the main cable and the deck system well and work in harmony;pedestrians will not produce resonance-like phenomenon when passing.There is no obvious discomfort;cable-pylon restraint mainly affects the bending moment at the bottom of the pylon,and the use of consolidation-sliding restraint can effectively reduce the bending moment at the bottom of the pylon;the use of both ends of the pylon and beam restraint is not a good restraint,and the better restraint is the consolidation-hinging or consolidation-sliding restraint.The influence of longitudinal beam section size on the static and dynamic characteristics of the pedestrian suspension bridge is not particularly obvious,the influence of the main cable section size on the dynamic characteristics of the pedestrian suspension bridge is relatively large,the design can be through static analysis,dynamic characteristics analysis to find the best section size,in order to achieve the purpose of optimal design.The conclusion provides a reference for the design and selection of pedestrian suspension bridges and the analysis of wind resistance and earthquake resistance.