Research On The Finite Element Model Optimization Of The Terahertz Antenna

At present,as a general method the finite element analysis(FEA)is used to predict the deformation performances of antennas.However,there are some structural parameter errors and some material property errors between the finite element model and the real structure of an antenna.Because of these errors,the FEA can't^realistically reflect the antenna performances under various loads.Therefore,only when the initial established finite element model of the antenna is highly consistent with the real antenna through optimizing and updating,can it be used effectively to predict the antenna deformation in high precision.In this dissertation,proposed is a parameters compound optimization method(PCOM)of the finite element model updating to address this problem.The method includes three steps:firstly,the parametric finite element model of the antenna is created,and the model is analyzed to ensure its reasonability.Secondly,the sensitivity analysis is carried out,and the highly sensitive parameters act as the optimization variables.Thirdly,the optimization function is established,and the compound optimizing is carried out with the zero-order method and the first-order method.In order to verify the feasibility of the PCOM,the paper takes the 1.2 meter terahertz antenna(a prototype model of DATE5)as an application example.The parametric finite element model of the antenna is established according to the real antenna structure,and the structural static analysis and dynamic analysis are presented.The analysis results have suggested that the initial finite element model is reasonable.Next,the sensitivity analysis of the material parameters of the antenna is carried out,and the parameters of the high sensitivity are chosen as the design variables.Since determining performance of the real structure antenna is extremely difficult,here the performance of the imaginary real structure of the antenna is the optimization object.And then,the PCOM is carried out respectively under different loads.The results have suggested that the performance of the finite element model is identical to that of the imaginary real structure of the antenna after the optimizing and updating with PCOM.Thus,the feasibility of the PCOM has been demonstrated.Moreover,it is expected that the PCOM can be extended to apply to the finite element model updating of the large aperture submillimeter-wave telescope.