| In this thesis, the modeling methods, as well as strength and collision problems of acertain type of EMU aluminum alloy car body are studied. The required FEM model of thecar body is established by researching the modeling method of hollow aluminum profile. Thesuitable load for strength analysis of the car body is obtained by comparing the domestic andforeign car body strength calculation standard. Then it is used finite element method toanalyze the strength of the car body. Finally, it studies the vehicle collision simulation basedon the dynamic model of the ANSYS WorkBench software.Firstly, the simplified geometric model of car body is established according to theexisting vehicle model. This part mainly aims at two kinds of commonly used modelingmethods of car body. Neutral surface method and section equivalent method are studied andtrial. Then the two methods are compared. The section equivalent method can guarantee theaccuracy of the calculation, greatly simplify the body modeling and do better in finite elementmesh quality than neutral surface method. And it can save the computer resource and time.Finally, the final simplified model of complex hollow aluminum alloy car body is establishedby using this method. It provides simpler geometric model for the next finite element analysis.Secondly, these standards such as the European car body design standard EN l2663,Japanese Railway vehicle car body design standard JIS E7106and our country TB/T1335and200km/h and higher speed railway vehicle strength design and test interim provisions arecompared. By comparing differences between the three kinds of standards on vertical load,longitudinal load and superimposed load, it is determined that EN12663standard is mainlyfor the aluminum alloy car body of EMU about strength calculation and design checking.Then, it uses the structural static module of ANSYS Workbench finite element analysissoftware which is suitable for engineering application to carry out strength analysis andstiffness analysis for the EMU car body structure. It is obtained that the maximum equivalentstress of the structure is less than the allowable stress of the material under various loadconditions. So, static strength meets the design requirements. And the frame structuredeformation of the car body is less than the allowable value. So, the stiffness meets therequirements. In the fatigue load conditions, transforming the multi axial stress to uniaxialstress and drawing the modified Goodman fatigue limit diagram of the materials according tothe ORE report, it is obtained that fatigue strength of the selected parts of the car body meetsthe design requirements.Finally, the collision simulation of vehicle body is obtained from the basic theory ofexplicit finite element algorithm and the technology of explicit finite element based ondynamic module of ANSYS WorkBench. Then the collision simulation results of high-speed EMU are analyzed. The results show that in the collision with rigid wall, the collisiondeformation of car body is small. The car body absorbs the collision kinetic energy andtransforms it into its internal energy. And the maximum deceleration of a front end wall pointis slightly beyond the maximum range of EN15227standard. But the duration time is short.So it can not cause fatal harm to both drivers and passengers and the car body can satisfy therequirements of the collision resistance. The car body can ensure the safety of drivers andpassengers in the collision process. In the two cars head-on collision process, the deformationof car body is small and the drivers and passengers have survival space. The total kineticenergy of back car is almost absorbed by the deformation of front end car and back car. Thetwo cars’ maximum accelerations of one point of the front wall are beyond the EN15227standard. But its duration is short. So, it won’t cause fatal damage to the drivers andpassengers. The car body can satisfy the requirements of the collision resistance and ensurethe safety of drivers and passengers in the collision process. |
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