Research On Dynamic Load Identification Technology Based On Regularization Method

In many structural vibration problems,such as vibration control,fault diagnosis,etc.,it isnecessary to determine the external excitation source,so it is of great significance to study the method that can identify the dynamic load acting on the structure.Among them,the time-domain method for dynamic load identification is not only intuitive in solving results,but also not limited by the type of load to be solved,so it has always attracted the attention of scholars.As an application of dynamic load identification technology in engineering practice,ice load inversion of ships in the ice area is facing the serious problem of inverse problem solving equations when using the time domain method for inversion calculation.Based on this,the main research work completed in this article are:(1)The ice load inversion algorithm is seriously ill due to the existence of factors such as the cross-regional placement of sensors and the position of ice load and the influence of noise on the response measurement data.Qualitative analysis,followed by the establishment of ice load inversion method theory and specific operation process based on Green kernel function method and Tikhonov regularization method.In addition,a simulation example of the external load identification of the local structure of the bow is designed in this paper.Under the condition that the model information,response information and loading position are known,the regular solution of the dynamic load is realized,and it has a good convergence effect,namely Effectively alleviated the ill-posed nature of the reverse equation.(2)In order to verify the effectiveness of this method in the actual ship test for solving the ice load,the ice load related monitoring test of the Xue Long icebreaker was carried out.During the eighth Arctic voyage,strain sensors were deployed The array monitors the hull structure response during the action of the ice ship,and the video image system identifies the location of the sea ice impact.According to the known hull structure model information,the transfer relationship between the response measurement point and the ice load action point is obtained,then the operator identification equation is established,and finally the ice load under the given response data is calculated by the method established in the article.The analysis of the calculation results shows that the method in this paper can effectively identify the ice load.The inversion of the ice load in this paper is compared with the ice load onicebreakers under the same icebreaking conditions abroad,which verifies the correctness and engineering availability of this method.(3)This paper also studies the cabin noise problem under ice load of the ship in the ice area,and carries out the measurement test of the cabin noise of the Xue Long icebreaker,The ice breaking process is divided into three stages,corresponding to the three states of normal navigation,ice breaking impact and ice crushing,and the effects of the three states on cabin noise characteristics are analyzed.