The Study Of Parameterized Model Towards The Frontal Crashworthiness Design Of Minibus Body Structure

Concept design phase is very critical to the guarantee of body structure performances when developing new vehicle. It is very difficult and costly in the following design phase if some deficiency had been earlier. Take the minibus produced in our country for example, when the CMVDR294(the design rule about the protection of occupant in frontal impact) was issued on Oct28 1999, nearly all can't meet the requirement. The fact powerfully shows that the frontal crashworthiness of these minibus has not been effectively controlled during concept design phase.In our country, the study of vehicle passive safety started recently and mainly focuses on the simulation of the whole vehicle, but such work has little effect on the development of product, especially the phase of vehicle concept design. Now the research of vehicle passive safety design is blank.But in other countries, several big auto companies already have the ability to guarantee products performances during all phases using CAE techniques. This method has greatly reduced the development cycle and cost, enhance quality.Under such situation and the demand to level up the ability of our vehicle passive safety, this paper supported by National Natural Science Fund GM China Science Research Fund "the study of crash dynamics simulation and passive safety measures of minibus" selects representative minibus as the research object, put forward a parameterized model towards the frontal crashworthiness design of minibus body structure. The key technique and the way to create model are studied in the paper and the application of the model is also discussed.From the point of research problem, its necessary to build the basic rules so as to control and master the whole study process.The model created should reflect the essence of study problem. Take the model created in this paper for example, it must be simplified for the use during minibus earlier concept design phase, but it should effectively simulate the frontal impact characteristic of the whole scale, other characteristics can be ignored.The parameters used in the model must be the main factors influencing the crashworthiness. If not the case, the distinguish of main parameters is difficult and the computing time is increased.From the point of view of concept design, the description of parameters should accurate and simple so as to evaluate and select several scheme, and decide the final result.The study on main factors which is critical to Minibus body structure frontal crashworthinessThe typical minibus is selected as the research object. The analysis begins from body structure and the results of vehicle frontal impact test and virtual test. After studying deeply, this paper select out the main factors which influence the minibus frontal crashworthiness through from two aspects consideration, energy-absorbing and longitude stiffness. Finally, the front member, front floor, and front door is the important factor which should built carefully in the parameterized model.the key technique of building parameterized model——the extraction of body structure stiffness parametersThe stiffness characteristics of body structures is the most important design parameters. According to the typical collapse mode of structure, This paper use Component FE method to acquire stiffness curves of axial and bending deformation. And the stiffness curve is simplified by several key parameters to meet the needs of concept design. Accordingly, we get axial collapse stiffness parameters(,,,) and bending collapse stiffness parameters(,).The establishment and validation of parameterized model for Minibus frontal impact analysisOn the basis of model analysis and the extraction of stiffness parameters, this paper build the parameterized model using PAM－CRASH, and the validation has been done by comparing deformation shape, rigid wall reaction force and the energy absorbed by body structure. The correlation is good.The application of parameterized model in Minibus concept d...