| With the proposal of "One Belt and One Road" strategy and the continuous advancement of urbanization construction in China,tower crane(tower crane for short)as the most important lifting equipment in modern construction,its market possession has been rapid growth.But because the tower crane works outdoors all the year round,the working condition is very hard,and it is in high intensity and high frequency work for a long time,which is prone to safety accidents.The analysis of several tower crane accidents reveals that most of the accidents are caused by their fatigue damage,resulting in serious casualties and property damage.So,it is very significant to study the way of experimentation on the dictates of the life of tower cranes.To prevent serious accidents caused by fatigue damage to tower cranes,the tower crane safety monitoring system has been widely used on various construction sites in recent years.However,the stress spectrum and residual fatigue life of tower crane cannot be obtained quickly when the real-time safety evaluation is carried out.To solve this problem,this article proposes a method to quickly get stress spectrum tower cranes.The method uses the finite element analysis technology to establish the stress data sample library according to different working conditions.On this basis,combined with the prediction algorithm,the equivalent stress value of the check point can be quickly obtained,which paved the way for the subsequent development of fatigue life estimation platform.In the last according to the data collected by the surveillance system and combined with the WPSO-SVM prediction model,the equivalent stress value of the check point is quickly obtained,and the remaining life prediction result is consistent with the actual,which provides a reliable basis for the regular maintenance and replacement of tower crane.This paper takes an in-service tower crane as the research object,and the main work is as follows:(1)According to the actual parameters of the tower crane,establish its finite element model,and combined with VC++ and ANSYS software to establish the tower crane finite element analysis platform,complete the static and dynamic automatic analysis of the tower crane.At the same time,the stress and displacement cloud maps in some typical working conditions were obtained,and the dangerous points of tower crane boom were determined,and these dangerous points were used as the fatigue check points for subsequent analysis.(2)An adaptive particle swarm optimization algorithm for SVM parameters(WPSO-SVM)is introduced,and then three prediction models,SVM,PSO-SVM and WPSO-SVM,are established respectively,and their prediction abilities are compared.(3)Combining VC++ and Access to build a stress data sample database for the tower crane,using VC++ ADO technology to achieve the platform to Access the stress data sample database.The stress data sample library was established under different lifting load steps,and then the merits of them were compared by using the prediction model.Finally,the lifting load step of 0.2t was selected in this platform to establish the stress data sample library.(4)VC++ software is used to integrate the fatigue life estimation process and develop the tower crane fatigue life estimation platform.Through the data of the monitoring system and the established WPSO-SVM prediction model,the equivalent stress value of the check point and the residual fatigue life were obtained quickly. |
