| Most mining dump trucks work on uneven gravel roads,which requires that mining vehicles must have sufficient structural performance to support their normal operation.The frame is the main load component of the mining dump truck in the working process,so its structural performance has a direct image of the work efficiency of the mining vehicle,so the frame must have high strength,stiffness and fatigue life and other performance to support the normal work of the mining vehicle [1].Therefore,in order to meet this requirement,it is necessary to accurately assess the strength and fatigue life of the frame structure before the mine vehicle is produced.The previous frame fatigue life prediction method was that the manufacturer put the sample car used for trial production in the development of new products in the laboratory for bench fatigue testing,or let it be tested when it was running on the actual road,but this method required a long time,high cost,and could not predict whether the structural needs were met before the vehicle was put into use.Taking the frame of the Type 240 mining dump truck as an example,the fatigue life prediction of the frame structure is carried out by means of finite element analysis,which realizes the joint simulation between Ansys,Adams and Ncode software,effectively avoids the shortcomings of traditional fatigue testing,and provides technical support based on CAE fatigue analysis for the design and optimization of frame structure.Firstly,the mining vehicle model established by Solidworks is simplified under the premise of ensuring the calculation accuracy and saved into x＿t format,and then imported into Adams to establish the vehicle dynamic model of the mining dump truck.According to the road conditions of most mining dump trucks in actual operation,this thesis uses random uneven pavement as the load excitation input condition,and sets the simulation speed to 20Km/h,after the simulation time is 40 s,after the dynamic simulation,the load spectrum of the position where the frame and the suspension connection with the relatively large force are extracted,and the input load is also provided for the subsequent frame fatigue durability analysis.After simplifying the frame model created by Solidworks software,it is imported into The Ansys software to form a finite element model of the frame.In this thesis,the hexahedral unit is used to mesh the mining dump truck frame,select the actual boundary constraints,and then analyze the strength of the three working conditions of the frame to see if the frame has sufficient static strength.The stress values measured by the experiment under the corresponding operating conditions are then compared with the stress values obtained by the simulation to verify the accuracy of the model.Finally,to analyze the fatigue life,the static stress value of the frame at the time of the unit load should be obtained,and then the time course load converted by the ASCII Translate converter should be corresponded to the quasi-static stress value one-to-one,combined with the S-N curve of the frame material,based on the nominal stress method theory,the fatigue life prediction of the frame was predicted by the timing load mapping method in the Ncode software.It is calculated that the mining vehicle can exercise at least 7.42 × 10^5km.The company’s requirements for the use of the mine vehicle frame stipulate that the fatigue life of the danger point is 500,000 to 600,000 kilometers,and it can be seen that the mine vehicle meets the company’s design requirements for the frame.Studies have shown that with the help of Software such as Ansys,Adams,Ncode,etc.,we can accurately predict the fatigue life of the frame before the production of mining dump trucks,which can not only guide the design of the frame structure,the development of new models,but also produce more cost-effective mining dump trucks.It is also possible to optimize the structure that does not meet the performance requirements in advance,and after improving it,the service life of the whole vehicle is extended. |
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