Research On A-type Frame Fatigue Parameters Interval Uncertain And Robust Design

In this paper,the object of study is a large-tonnage mining truck,relying on the National 863 Program "the large-tonnage dump truck development".Mining dump Truck is the main force of transport in the large open-air ore field.In order to promote the development of independent products,the mining equipment is included in the 16th national congress of major technical equipment in key areas by the state council.Therefore,the use of advanced technology research to develop mining dump truck,is in line with national policy requirements and has important engineering value.Traditional design mainly uses the deterministic material parameters to carry out the structural fatigue life analysis and deterministic optimization,without considering the structural fatigue life dispersion caused by the uncertain variables,while the fatigue life is robustly designed to take into account the unavoidable.It is a kind of uncertain optimization design method which considers the reliability of the structural fatigue life.Therefore,the design of the fatigue life is more overall and the engineering value than the traditional optimization design.In the practical application,it is found that the life of the A-type frame of the key parts of the dump truck is inconsistent.A-type frame is the main bearing parts of the mine dump truck,bear a strong impact from the road,in the event of cracking or broken,the normal operation of the vehicle will be seriously affected,resulting in millions of significant losses or even casualties,so guaranteed It is critical to reduce the fluctuation of the uncertainty variable beyond the fatigue life of the operating process.For the special structure and working conditions of one domestic mining dump truck,this paper combines experimental work and numerical simulation technology with A-type frame fatigue parameters interval uncertain and robust theory to research fatigue robust design of the parts of a mining dump truck.This paper mainly focuses on:1.The rigid and flexible coupling dynamics model of A-type frame,frame and rear axle housing is established,and the accuracy of the model is verified by comparing the simulation results with the simulation results.At the same time,according to the actual working conditions of the mine and the operation of the dump truck,the road surface composition of the whole working condition taking into account the loading conditions is constructed.Based on this,the load spectrum information of the key hinge point of the A-type frame is obtained.Fatigue life analysis and robust optimization design laid the foundation.2.Considering the uncertainty of weld fatigue parameters of A-type slab,the method of determining the fatigue parameters of high-precision weld is established by combining Manson-Coffin formula.Firstly,the fatigue life test of welding specimen based on strain control is carried out on the biaxial fatigue testing machine.Secondly,for the fatigue of the fatigue life test data and random uncertainty,a small amount of test data is randomized and the original sequence is extended and genetic Finally,the accuracy of the method and the rationality of the uncertainty of the weld quality parameters are confirmed by comparing the predicted data with the experimental data in this paper.The results show that the fatigue parameters of the weld are obtained.Later A-type fatigue life range prediction and fatigue robust optimization design to provide accurate fatigue parameters range.3.The finite element model of the welded specimen is established.Based on the experimental conditions,the necessity of the weld unit and the feasibility of the weld modeling method are verified.Secondly,according to the above weld modeling method,The finite element model of the weld and the weld is not taken into account.The stress test of the A-type vehicle is carried out by the electric measurement method.Through the comparison of the stress simulation and the test results,it is verified that the A-And then based on the load spectrum obtained by the above-mentioned model,the ε-N curve of the component is modified according to the fatigue life test of the A-type welded joint specimen.Based on the interval in this paper,considering the weld uncertainty The fatigue life prediction of the A-type frame is improved and the prediction accuracy is improved.Finally,based on the interval bounds obtained above,the accurate interval stress,strain and fatigue life of the A-type frame are obtained.Later,the sound optimization design laid the foundation.4.The sensitivity of the original A-type frame structure is analyzed,and the uncontrollable variables with high sensitivity are selected to participate in the optimization.Then,the fatigue life of the A-type frame is calculated for each group of controllable variables.,The mathematical relationship between the A-frame and the optimization variable is established by using the response surface method.The robust optimization design idea is introduced into the design and development of the A-type frame of the mine dump truck,and the interval fatigue robust optimization model is established.Finally,Model to solve,to achieve A-type frame fatigue robust optimization design.