FEM Correction For The Guyed Mast Structure Based On Optimization

The guyed mast is an extensive used tall and slender structure,which tends to generate wind-induced fatigue rupture that may cause the collapse of the whole guyed mast.Therefore,the avoidance of the wind-induced fatigue rupture to secure the guyed mast structure has become the advancing front of civil engineering.So it has deep influence and wide application field to set up a system of safety pre-waming for guyed mast structure.However,FEM correction is the foundation of realizing guyed mast's safety pre-warning.In this thesis,the problem is taken as engineering background to study the FEM correction of guyed mast structure.In the process of the calculation of the guyed mast' wind-induced fatigue,the structural finite model is just theoretical,and this theoretical model is different from the actual structure.There are some differences between them.In the guyed mast' wind resistance design,these differences are inessential if they are within the error permission.But in the system of safety pre-warning for the guyed mast' wind-induced fatigue,these variances can be vital,and they could result in the failure of the whole safety pre-warning system.Therefore,the establishment of the FEM correction method for guyed mast will be significant.As the steel structural model error mainly relied on the member bar's link stiff and not on its physical dimension,this paper expatiate on the FEM correction method,which select the joint link stiff as the damage indicator, and use the means of optimization principle to realize the structural model correction.This paper establishes the guyed mast structure's calculated model,this model uses nonlinear element,and considers large deflection of the cable and the stress stiffening and coupling effect between cable and tower.Then,we can get the node's response of the mast body by carry on the non-linear dynamic analysis to this model.In conclusion,this calculated model could reflect the basic character of practical structure by analyzing the node's displacement response time histories and displacement spectrum.The bars of the body of mast are separated into five parts,and these five part's element stiffness matrix could be determined by calculation,on which foundation,the space FEM of truss structure that based fixity factor is determined.Applying the method of optimization,the minimum differences between the displacement response of calculated model and practical structure were chosen as the objective function,and take the member bar's joint link stiff as modify parameter,and the finite element model is corrected.According to the research of this paper,optimization principle can be well adapted to structural FEM correction.