Research On Cable Force Identification Considering Complex Boundary Conditions

In recent years, with the rapid development of our country construction enterprise,wire rope is widely used in engineering structures, such as cable-stayed bridge, arcbridge, suspension bridge, big span roof, glass curtain wall, etc. The cable tensionwhich is the main stress components is the key to the safe operation of the controlcable structures. The influence of boundary conditions of lasso should not beneglected for the dynamic the cable tension, especially for the lasso which cabletension is smaller or the length is short.To study the cable tension identification considering the complex boundaryconditions, in this paper the main work is as follows:First of all, elaborated this paper research background and significance of topics,described the completed test commonly used method, and mainly introduced thefrequency method and frequency method research situation of the cable forcemeasurement.Secondly, introduces the basic theory of free vibration of simple beams, sets upthe vibration equation of beam bending and solves the equations of motion. And then,solve the equations of motion, considering the four kinds of different boundaryconditions,get vibration function respectively, and draw their first four image modeaccording to the vibration function.Thirdly, when the cable section is larger, it established the cable vibrationequation, considering the cable bending stiffness, which is according to the Eulerbeam model of axial force. Considering three different boundary condition, thenumerical method was used to solve vibration equations combining with theMATLAB and Excel. Getting: The cable tension identification of lasso practicalformula on both ends hinged boundary conditions and the cable force-out-of-planerelationship formula of natural frequency of vibration; Practical formula for cableforce identification on fixed ends meet boundary conditions and the reference table ofan,bn; The cable tension identification formula on both ends of the elastic boundaryconditions, relevant charts, and analysis.the results. Fourth, the multi span cable model was established, considering the influence ofthe cable bending stiffness on natural vibration. By the natural vibration differentialequation of single span and the boundary conditions of each span, it gets the vibrationequation two span and three span respectively.In the end, Lasso Models are established by the finite element method in differentboundary conditions. The vibration of the cable model is established in solidboundary conditions by ANSYS simulation. The cable tension identification formulaswe have got are practicability and reliability which are verified through numericalexamples.