Autobody Part Parametric Modeling Method Inspired From Stamping Process

The establishment of 3d model of body parts is only the beginning of a series of complex iterative processes.The engineer will make repeated modifications based on the feedback of subsequent structural analysis,NVH analysis,etc.,which is a very time-consuming process.The existing parametric modeling methods are far from being able to adapt to the complex and changeable characteristics of body parts.Therefore,exploring more efficient modeling methods has become an important choice for automobile companies under great competitive pressure.Based on this background,this paper explores a new modeling idea in cooperation with the R&D department of an automobile company and implements the software.The traditional process of creating 3d models of car body parts is more similar to the serial modeling process based on "point-to-line,line-to-surface and plane-to-body",so as to achieve some "shape expectation" of engineers.Such shape prediction may be proved to be defective or even wrong by later analysis.Because the whole modeling process adopts the history-based modeling mechanism,the cost of late modification is very high and the robustness of model editing is very low.To solve these problems,this paper proposes and implements a parallel modeling mechanism based on "functional decomposition".The modeling process is redefined from a design perspective,and the model is decomposed into matrix and some additional structures.Specific and structurally adjustable entities are used to represent the installation requirements of different assemblies,and independent geometric operations are carried out on them to complete the model design of body parts.To solve the above problems,this paper proposes and implements a parallel modeling mechanism based on "functional decomposition" instead of "shape expectation".In this study,the modeling process of body parts was redefined from the perspective of design rather than modeling,and the model was decomposed into matrix and some additional structures generated for accessory assembly.Specific and structurally adjustable entities are used to represent the installation requirements of different assemblies,and the final 3d model of body parts is completed through a series of independent solid based geometric operations.This project is based on Siemens NX platform to realize the above mechanism,and integrated as part of Siemens NX modeling system.The algorithm part of this paper is completed by Visual C++ under the architecture of NX Open and UFun.The system integration and optimization part is completed by Knowledge Fusion and the entity library is completed by PTS.The final test was completed in the main engine plant.Compared with the traditional method,the mechanism in this paper showed obvious advantages,especially in the case of major structural modification in the case of accessory change.The main innovation of this paper is to achieve a parallel modeling method based on functional decomposition rather than shape expectation.Compared with shape expectation,functional requirement is a more stable factor in the modeling process,and the modeling strategy based on the latter has higher model modification efficiency.Although the development of this paper is based on Siemens NX,it is common to problems,and its ideas and methods are referential.