Parameterized Design And Structural Optimization Of Telescopic Boom For Multi-terrain Vehicles

The multi-terrain telescopic boom lorry loader is a kind of cargo handling equipment that needs to adapt to various terrain conditions.In order to meet the trafficability of the road conditions,the chassis mechanism of the vehicle is more complex and the weight is relatively large,so the mass of the upper part is limited.In addition,since the telescopic boom structure is located on one side of the upper body,the overall layout space of the boom is limited,which makes it necessary not only to ensure sufficient bearing capacity,but also to meet the lightweight requirements in the process of designing the telescopic arm of the lorry loader.Therefore,the finite element analysis and structural optimization of the telescopic arm has important practical significance.Using the finite element method to simulate and analyze the telescopic boom structure can prompt the possible problems in the structural design and provide the basis for the optimization of the structure.In the optimization design of telescopic boom structure,the traditional methods often change the geometric model of the structure first,then re-establish the finite element model for calculation,and makes repeated attempts one by one.This method leads to a large number of repeated modeling and calculation,and the work efficiency is low.For this reason,an efficient modeling and optimization design method is needed,which can quickly establish a new finite element model after changing the structural parameters of the geometric model,and combined with modern optimization algorithms to achieve multi-objective optimization of the structure.In this dissertation,according to the existing telescopic boom structure of multi-terrain vehicle and the three-dimensional model of the boom,the integral finite element model of the telescopic boom with high quality is established by using Hyper Mesh software considering the complex contact and constraint boundary of the structure,and the finite element static analysis is carried out under eight working conditions.Through the preliminary check of this telescopic boom,the overall stiffness of the structure is found to be the weak point of the boom performance.Subsequently,stress test is conducted on the telescopic boom structure,and the errors between the test results and simulation results are analyzed to verify the validity and correctness of the finite element model and analysis method of telescopic arm.In order to facilitate the modification of the telescopic arm model in the process of optimization and realize the rapid establishment of the telescopic arm finite element model,on the basis of the existing geometric model and modeling scheme,the parameterized telescopic arm finite element model is established by using the macro recording method in ABAQUS software.The finite element model includes complex structures such as telescopic arm head,arm tail and telescopic cylinder support,as well as contact information of each slider.The whole process from the establishment of geometric model to finite element model is completed,and the whole parameterized finite element model of telescopic arm is established.When the geometric parameters of components in the model need to be changed,a new finite element model can be generated automatically by modifying the corresponding parameters in the parametric finite element model.Based on the second-generation non-dominated sorting genetic algorithm(NSGA-II),the optimal Latin hypercube experimental design method is selected to sample the relevant geometric dimensions of the telescopic arm with the help of Isight optimization software platform.And the response values of the sample data is obtained by the parameterized finite element model,and then the approximate model of radial basis function neural network is constructed.Through this approximate model,based on the requirements of lightweight,aiming at improving the stiffness of the boom structure,the optimization of the boom parameters is completed.The optimization results show that under the condition of meeting the lightweight requirements and the allowable strength of the material,the maximum deformation in the luffing plane of the telescopic arm is reduced by 26.5%compared with that before optimization,and the stiffness of the telescopic arm is significantly improved.