Study On Concept Design Method Of Automobile Frontal Crash Based On Lumped-parameter Model

With the improvement of our automobile’s design standards, the shortening ofproduct’s design cycle and quickly launching of new car have become an urgent need forthe automobile enterprises to achieve the occupation of market shares and obtain largerprofit space. As one of the four major parts of the automobile, the body structure is animportant part during the car designing, it is also an important carrier to ensure the collisionsafety performance. The form of the body structure of the car need to be fixed during theconcept design stage, therefore, the study on concept design method of automobile is ofgreat importance to ensure the improvement of the car collision performance. Structurecollision performance, as an important index to the assessment of the safety performance ofthe car, is very difficult to design. It is barely impossible to do modifications during thedetailed design stage of the car; therefore, setting the collision performance as the targetduring the concept design process is of great importance for the improvement of collisionsafety abilities and the shortage of product’s design cycle.Based on the Science and Technology Development Program of Jilin Province“Dual-mode Parameteral Library Building of Car Body Parts and Study of FastOptimization of Crashworthiness”(ID:20126001) and the FAW R&D Center project “TheEstablishment and Optimization Analysis of the Collision Concept Model of the PassageVehicle”(ID:1332A), a Lumped-Parameter Model (which will be referred as LPM in thefollowing paper) is developed in this paper, which will be used in the concept design stage to conduct the prediction and assessment of the frontal crash collision performance of theautomobile. A4DoFs LPM of a domestic independent research and developmentautomobile is established; the accuracy of the corresponding model is also verified. Themain contents of this paper:(1) The corresponding areas and current research conditions of the domestic andforeign automobile body concept design is comprehensively summarized in this paper, thebody concept design method based on the LPM is further discussed in this paper. During theconcept design stage of the front crash automobile, the LPM functions as the preliminaryassessment of the realization of the collision performance of the car body, it also controlsthe axial stiffness distribution of the car body. Based on the performance characteristics ofLPM, the feasibility of the establishment scheme is analyzed and the2DoFs LPM of theenergy absorbing part in the head part of the car is preliminarily established.(2) The methods and implementation ways of the finite element simulation of thewhole car is discussed, a certain kind of domestic independent research and developmentautomobile is used as the subject of the research to establish the detailed finite elementmodel of the whole car, the collision simulation analysis is also conducted. The collisionperformance of the key parts of the car is analyzed during the front crash process, whichincludes the energy absorption and force transfer path of the key parts, it is used as thereference information for the multi-DoFs LPM of the whole car. The resulting data of thecollision force, displacement, velocity and energy response of the finite element model ofthe whole car is extracted.(3) The4DoFs LPM establishment scheme is defined based on the analysis of theenergy absorption and force transfer path during the front crash process of the whole car.Improved design for the material property of the spring and the method of the stiffnessassignment in2DoFs LPM modeling scheme, the4DoFs LPM of the actual car model isestablished and the collision analysis is also conducted. Comparative analysis between theLPM and the actual car detailed model’s collision performance results is conducted to verify the rationality of4DoFs LPM modeling method. LPM parameterized modeling scheme anddetailed implementation process for automobile concept design based on the LPM areformulated.The research contents in this paper involve the design of the automobile body, they canbe generalized as the collision analysis researches during the automobile concept designprocess, which involve a simplified and centralized parameter modeling LPM. During theconcept design stage of a new car, the collision performance of the car in the front crashprocess is quickly analyzed and evaluated through the establishment of the multi-DoFsLPM of the whole car. It can also be used to further conduct and promote the structuraloptimization design of the car on the base of security.