Research On Load Identification Of Thin-walled Stiffened Structures Based On Regularization Method

As the main carrier of air and space transportation,launch vehicle is one of the main directions of my country’s development in the aerospace field.At present,the launch vehicle mainly adopts a bundled structure,that is,the booster rocket is bundled on the core stage of the rocket to provide thrust for improving power and controlling attitude.The drastic change of thrust will have a greater impact on the core stage,and the core stage is hard.Shell structure,so when the thrust of the booster rocket is deviated,it will affect the attitude control of the rocket.Excessive thrust deviation may even cause local buckling of the core stage and eventually cause damage.Therefore,mastering the load of the core-level structure plays an important role in improving the rocket launch success rate,improving the cost-effectiveness of the carrying capacity,and the design of the rocket structure.However,in actual engineering,it is difficult to directly measure the load information of the booster rocket to the core stage,so it is necessary to study the inverse calculation load of the simplified connection.Load identification,system parameter identification,and dynamic characteristics modification are inverse problems of vibration.The inverse problem is different from the traditional forward problem analysis method.It uses the dynamic response of the system and the dynamic characteristics of the system to calculate the excitation of the system.Aiming at the ill-posedness of the system matrix in the process of load identification,this paper introduces a direct regularization method,and establishes a load identification method for stiffened structures based on truncated singular value method and Tikhonov regularization method.Use structural system information and strain response to reconstruct loads.First of all,the verification was carried out on the stiffened slab structure.By comparing the recognition accuracy of different recognition algorithms,the load recognition algorithm based on the generalized cross-check method was selected.Secondly,against the background of large-scale rocket core stage external load identification,based on the generalized cross-check identification algorithm,the static/dynamic load identification of the large-scale thin-walled stiffened tube structure is carried out,and the verification shows that the identification algorithm can well detect the load level and load.The direction is recognized.Finally,for the optimization of sensor layout,a screening method based on the EID method is proposed.In this paper,through the study of static load and dynamic load identification,the load identification algorithm of large thin-walled stiffened structures is improved and developed.The verification results show that the recognition algorithm has good noise immunity and effectiveness,and the proposed method for screening measuring points has good effectiveness and applicability.