Fatigue Analysis Of Concrete Main Towers Of Cable-stayed Bridges With Wind Vibration

With the pursuit of bridge structure on the economic and aesthetic gradually developing,engineers have to consider the limit design principle,to meet the loading requirements.Structure should satisfy the stability of the structure itself,and also requirements for the material structures with high strength,light weight.It is therefore to take into account the material structure in use process,to investigate that if the structure suddenly fails,especially for some high pier,tower and long-span flexible structure,more necessary to consider the effect of load under the action of structure reliability.For high pier,there are no the wind resistance fatigue analysis on reinforced concrete structures so far to the necessity for wind load of fatigue analysis,requires a further analysis and research.Objective: to sum up predecessors of wind load simulation theory,the wind load simulation with simple harmonic form,through Midas Civil/FEA finite element software of cable-stayed bridge main tower cable-stayed bridge model is established and loaded,and analyzing the eigenvalue problems,to get the dynamic response of the main tower key parts,and determine the most unfavorable load position of the main tower under wind load;Through Midas FEA finite element software of main tower the most unfavorable position do local fatigue analysis and calculation,fatigue life and any,applied to the fatigue reliability analysis of cable-stayed bridge main tower,eventually to investigate whether it is necessary to consider the wind load of the structure of reinforced concrete main tower fatigue effect.Methods: applied the Davenport wind speed spectrum and Shinozuka theory,the harmonic synthesis method was used to simulate the wind load,and wind calendar generator WINDHIST PRODUCER V2.0 respectively simulate the fluctuating wind speed time history curve,and total time history curve of wind speed and wind pressure time history curve;Using a second order moment method improved calculate structure reliability index of the main tower,and determine the stability of the structure.Results: taking an example of cable-stayed bridge as the background,consider its under wind load,the fatigue analysis of the main tower structure calculation;Finally using the reliability theory of fatigue reliability of the analysis of the main tower of the bridge,conclude that for the high pier structure,can't ignore the role of wind load.The higher the fatigue analysis of cable-stayed bridge main tower structure is valuable,which can predict higher position about optimization of structures.Jane harmonic superposition method was used to simulate the wind load effectively,in line with the engineering practice,for the wind load of high pier structure dynamic analysis to provide the reference.