Multi-scale Finite Element Model Updating Of Cable-stayed Bridge Based On Cable Force Response Surface

The finite element model updating technique can modify the geometry,material properties and boundary conditions of the initial finite element model according to the static and dynamic response of the actual structure,so that the modified finite element model can reflect the mechanical state of the actual structure precisely.Multi-scale finite element model updating can reduce the computational complexity and reduce the model error effectively to ensure its calculation accuracy.In this paper,the modeling strategy of multi-scale finite element model of cable-stayed bridge is mainly studied.A multi-scale finite element model updating technique based on cable force response surface is proposed.And the numerical simulation of the single tower cable-stayed bridge in the laboratory is carried out to verify the above research contents.The main research contents are as follows:(1)The method of small scale finite element analysis model of cable-stayed bridge based on sub-model technology is discussed in this paper.Taking the single tower cable-stayed bridge in laboratory as research object,the sub-model of the cable-girder anchorage zones is established and studied.The results show that the sub-model method can effectively analyze stress distribution of the complex area.(2)Based on the consistent modeling strategy of the multi-scale finite element model,the multi-scale finite element model of cable-stayed bridge is founded by multi-point constraint method,and the multi-scale analysis of cable-stayed bridge is realized.Combined with numerical examples,the multi-scale model and the sub-model are compared and analyzed.The results show that the multi-scale model is more convenient and effective than the sub-model,and the calculation result is more accurate.(3)The cable force response surface is set up according to the polynomial function and a new multi-scale model updating method based on cable force response surface for cable-stayed bridge is proposed.It is proved that the method is feasible and effective by numerical simulation.The modified parameters can maintain a clear physical meaning,and the correction target is specific and the correction effect is good.