Study On FE Model Modification Based On Gauss's Process Regression Theory

In the field of engineering,FE model is widely used in construction and scientific research.Any model which is capable of reflecting the real working station of structure is the original motion of scientist.As for bridge engineering,the actual working state of the bridge(the quality of the construction and the real stress characteristics)is often tested by the load test.It is commonly acknowledged that the results of FE model is different from that of load test,it is necessary to reduce or solve the direct gap between the actual force performance of the bridge and the theory by means of model correction.The Gauss process regression method,similar to the response surface method,is based on a finite number of input and output tests,thus fitting the function relationship between the structural response and the model parameters.Because the FE model of the complex civil engineering structure contains many parameters,the experimental design and the regression fitting results are directly related to the accuracy of the model correction results.In this paper,firstly,based on the Gauss process regression and global sensitivity analysis,the MATLAB FE model revision software GMU is developed.By comparing with the example of response surface method,the superiority and accuracy of the results of the regression analysis are verified.Secondly,the prefabricated T beam structure FE model and cable-stayed bridge are taken as examples to establish FE metal model,meanwhile,global sensitive analysis is utilized to study parameter influence and optimization algorithms like Rosen gradient projection method and genetic algorithm toolbox is adopted to obtain the optimal parameter of FE model.Thus the process FE model modification is achieved based on actual load test data.The results show that for the fabricated T beam structure,the true stiffness of the main girder is larger than the design value.In order to ensure the overall force of the structure,the design and construction of the wet joint is the key factor.For large and flexible bridge structure,the initial model is generally of sufficient accuracy.