Mini Truck Body Structure Analysis And Improvement Design Of The Fatigue Crack

Mini truck body is one of the key assembly, the structural reliability and to protect life and property safety of users of great significance. Therefore, to be followed in the design of reliable, safe and economical design principles. In this paper, a company developing a minivan, for example, finite element analysis and reliability of the road simulation test to the body structure, power transmission line as a reasonable design ideas in order to judge the strength and stiffness criteria as indicators of the reliability of body structure . In addition, analysis and improvement of the body structure design process, applied to the following aspects of knowledge as innovation of this paper.(1)Using MSC.Nastran software selection and reasonable CWELD element to simulate the body structure solder joint connection, to ensure the accuracy of CAE model of the premise of reducing the modeling time.(2)Reversed in the calculation of the static condition, the choice of such displacement rather than the reverse torque to simulate conditions because of different structural forms of vehicles the boss by a certain height or a certain depth of the pits, due to its rigidity exists differences, so the actual commitment of the torque is not equal. Simulation methods such as displacement by more description of the vehicle's actual stress situation.(3)In finite element modeling, give full consideration to the accuracy of the model, such as the windscreen of the simulation, considering the glass adhesive sealant for the anisotropic material, in order to ensure the accuracy of the simulation, it is in the modeling when it removed.(4)Mode of calculation of body structure, the paper introduces a new mode calculation method, constrained mode shape method. Taking into account the actual operation of the car, not only by the size of payload mass, but also by the constraints of limited suspension system, so the quality of this paper and bound with a load of the vehicle structure has been constrained simulation mode. The calculation of modal constraints in the domestic automotive industry is still rare.The main contents of this paper include the following:(1)Body of the mini truck and simplified geometric model(2)Using finite element analysis software hyperworks of discrete geometric model, choose the right unit and solder joints to simulate.(3)Finite element analysis of body fat were calculated bending conditions, to reverse the conditions, constraints, modal and free mode, and the structural strength and stiffness analysis.(4)Finite element simulation results of the analysis, road test the reliability of the car. (5)In the simulation calculation and reliability of the road test on the basis of the irrational structure of the body that suggest improvements.This mini-truck body structure to solve problems, whether in theory or in practical application, have a relatively important reference value.