| The CAE technology which includes the finite element method is a powerful tool to analyze the structural problems. The value of CAE analysis technology is that we can set up basic computer analysis model in the product development stage. We can make strength analysis, life analysis, kinematics simulation and dynamics simulation on the designed product in order to obtain various performances. And the technology can also guide product design and shorten the design cycle.In the paper, the author set up the overall structure model of the semitrailer tractor based on the relevant research at home and abroad. The author also made a static and dynamic test for the semitrailer tractor in order to provide practical basis for the finite element analysis. And the test can also verify the correctness of the finite element model. Using the verified FEM(finite element model), the author analyzed the stress distribution and deformation of the tractor in bending condition, twisting condition, emergency braking condition and emergency turn condition. And the author made modal analysis on the overall structure of the tractor.The paper focuses on how to set up the FEM of the overall structure. Compared with the FEM of the frame, axle and so on, the overall structure FEM has the characteristics of large-scale calculation. And the model has difficulties to simulate the connections and assembly relations between the components. In this paper, by simplifying the geometric model and controlling the finite element cell size, the author found the balance between the size of the calculation and accuracy. In the progress of connecting and assembling, the author connected and assembled those models of the parts by rigid connections and coupling after importing, translation and rotating. Finally, the overall structure FEM was set up.In conclusion, the overall structure FEM can more accurately simulate the real working condition of the tractor. And we can more correctly grasp the stress distribution and the static and dynamic characteristics of the overall structure and the parts. |
