Building And Crashworthiness Analysis For Crash Conceptual Model Of Passenger Vehicle

With the high-speed development and overall improvement of the global automotiveresearch and development level, enhancing vehicle safety performance and shortening productdevelopment cycles have become a problem for the automotive engineers to solve. Vehiclefrontal development and design is broadly divided into three stages: conceptual design,detailed design and the late product improvement. Conceptual design is the basis and animportant stage for automotive design, just like the foundation of the building. It’s animportant part of the automotive design. Conceptual design stage requires the determinationof the car body’s overall layout, the overall dimensions, and the prediction of vehiclecrashworthiness on a macro level. Structural crashworthiness is the key factor of the vehicledesign. It relates to the safety performance of the vehicle design and it is a non-linear problemof multi-disciplinary cross. Because it is hardly to make changes in the detailed design stage,looking for a reliable agent model to simulate the vehicle’s crashworthiness in the conceptualdesign stage is of important significance.With the support of Science and Technology Development Program of Jilin ProvinceDual-mode Parameterized 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 Vehicle (ID:1332A), this paper develops a Lumped-Parameter Model (it will be shorten as LPM below)using for a car frontal crash crashworthiness prediction and assessment in conceptual designstage. This model is able to meet two deformation forms of the car frontal collision, the axial crushing and plastic bending deformation. Then the modeling method with a secondarydevelopment to automate the processes is conducted and the accuracy of the simplified modelis verified. The main contents of this paper include:The Research status of the vehicle body conceptual design around the domestic andforeign countries is analyzed and compared in this paper. It also explores the importance ofconceptual design in the full vehicle design process, researches the traditional LPM methodsand plastic hinge bending deformation mechanism, proposes the improvements of LPMmethods, which is used in automotive collision analysis in conceptual design stage. This papertries to establish a LPM with energy-absorbing parts in front of the vehicle body with4degree of freedom for the first time, and then analyses the collision simulation, summarizesthe modeling process and software operating methods.The deformation mechanisms of the plastic hinge bending in the front rails during theautomobile crash are comprehensively studied and modeled simply. A simplified model ispresented and its veracity is verified. The innovative introduction of the plastic hinge structureinto the LPM makes the LPM be able to produce axial crushing deformation and plasticbending deformation, meeting the deformation mechanisms of the vehicle collision.A certain kind of domestic independent research and development of A-class car is usedas the research object, and a detailed modeling guideline of preprocessing on the finiteelement model of the whole car is made. Finally, the detailed finite element model of thewhole car is established, which is submitted to LS-Dyna to conduct collision simulationanalysis. A LPM with plastic hinge structure is established based on the practical structure ofthis car, avoiding the drawback of producing one-dimensional deformation by the traditionalLPM and realizing simultaneous simulation of axial crushing deformation and plastic bendingdeformation during the vehicle collision. The computational results show that the response ofthe established LPM is consistent with the detailed finite element model to satisfy therequirement of conceptual design.In order to improve the efficiency of the establishment, revise and analysis of the LPMduring the conceptual design, a study on the LPM is conducted in view of the proposed modeling approach. TCL/TK language and Process Studio are used to realize the processautomation of LPM as the secondary development on Hypermesh. The parameters of thecomponents mainly include stiffness, size and weight. The resulting k files in Ls-Dyna format,which is produced by the modules, can be submitted to be computed directly. To verify thebroad applicability of this modeling method, this secondary development software is appliedto various vehicle models and work conditions for simulation. The results show that themodeling method can satisfy the precision requirement of the conceptual design and guide thedetailed design in the later period.