Research On Lightweight Design Of U-shaped Cargo Box Structure For Mining Dump Trucks

With the proposal of the national energy-saving and emission reduction strategy and the increasing fuel prices,lightweight design of vehicles has become a key research topic.Mining dump trucks belong to mining specialized dump vehicles,which have the characteristics of heavy weight and strong transportation capacity.As the main loadbearing component of mining dump trucks,the cargo box accounts for about one-third of the total weight of the dump truck.Therefore,conducting lightweight design research on the cargo box of mining dump trucks can reduce fuel consumption and enterprise costs,while improving the operational flexibility of mining dump trucks,which has significant research significance.Firstly,this article provides an overview of the development status of mining dump trucks and their cargo containers,the analysis and prediction of fatigue life of dump trucks,and the research status of lightweight design methods for dump trucks.In response to the actual design needs of enterprises for mining dump trucks and the shortcomings in the current design method research process,the necessity of researching the lightweight design method for the cargo box of mining dump trucks is elaborated,and the main content and framework of this study are proposed.Secondly,structural analysis is conducted on the 9.8 tons container,and a parametric model is provided for the optimization design analysis of the container based on parametric design theory.Furthermore,based on the Workbench software,the parameterized geometric modeling is simplified,meshed and loaded with boundary conditions to establish the finite element model of the container.Then,statics analysis is carried out for four important working conditions: full load uniform speed driving,critical lifting,emergency braking and extreme turning.In addition,modal analysis is also carried out for the cargo box.The finite element analysis results indicate that the cargo box has significant design redundancy and good dynamic performance,which will not cause resonance.Once again,based on the performance analysis results of the cargo box,a lightweight design method for cargo boxes under multiple operating conditions is proposed by comprehensively adopting experimental design,approximate model technology,and multi-objective optimization methods.Firstly,the main design parameters of the cargo box are selected through sensitivity analysis;Based on the Latin hypercube sampling method,obtain the sample space and calculate the response value;Then establish three approximate models: neural network,polynomial,and Kriging,and compare their accuracy;Finally,based on the neural network approximation model,the optimization objectives are to minimize the weight of the cargo box and the maximum stress under four working conditions of the cargo box.The multi-objective optimization is achieved using the MOGA optimization algorithm,and several sets of design schemes are obtained.Finally,in order to select the optimal design result among all lightweight design schemes,the stress fatigue life of the cargo box is introduced as a new evaluation indicator.In order to reduce computational complexity,orthogonal experiments were used first,and based on range analysis and variance analysis,the impact of all design parameters on the fatigue life of the cargo box was preliminarily obtained;Based on the Bayesian optimization algorithm,the optimal parameters of SVR are determined,and a fitting model for the fatigue life of the cargo box is constructed using BO-SVR to obtain the cargo box life of all lightweight schemes.The cargo box optimization design scheme is selected.The research results show that the optimized cargo box meets the design requirements in terms of statics and dynamic performance.With a slight reduction in fatigue life,the total mass is reduced by 333 kg,with a decrease of 3.39%.The thesis has 50 pictures,21 tables and 82 references.