Automatic Modeling Tool For Hood Inner Panel Based On Rib Stacking And Self-fixing

This research focuses on the automatic design of the hood inner panel.The design ofhood inner panel is an important part of body design.On the one hand,hood inner panel has various forms and complex structure,on the other hand,it is related to collision safety,vehicle NVH and many other performances,which need to undergo repeated demonstration and modification in the design process and is full of uncertainty.Complexity and diversity lead to extremely inefficient and time-consuming modeling process,which limit the number of evaluation,modification and remodeling in the task cycle and improve the design risk.Therefore,it is a general requirement of the industry to replace the conventional manual modeling process with efficient automatic modeling program.It can improve the efficiency and reduce the design risk through more analysis and iteration in the task cycle.Under this background,this research is carried out through the cooperation with the R&D Department of a domestic car enterprise.This project will develop the parameterized and automatic design module of the main structure of the hood inner panel for the most typical configuration schemes in the enterprise,and ensure that the design result has the ability of the automatic optimization in the later stage.First of all,the complexity of manual modeling of hood inner panel often exceeds 1000 modeling steps,which brings uncertainty to the modeling process.The processes are different for different modeling,and if the parameters are different,the same models have different modeling steps.Although the models and the parameters are the same,each modeling step is also different.Therefore,the common pattern of manual process can not deal with the complex and diverse structure of the hood inner panel by program cloning.In view of this,through the idea of engineer's modeling as a reference,this research designs a set of parallel modeling strategy based on rib combination for computer,which transforms the complex and specific manual modeling process into the repeated combination of geometric elements of the same configuration,and avoids the intuitive judgment necessary for manual modeling while exerting the advantage of computer efficiency.At the same time,the surface quality is another kind of problem that can not be avoided in the design of the hood inner panel.This project proposes a "curve and surface secondary reconstruction" mechanism based on the acceptable error,which significantly improves the surface quality and the success rate of subsequent operations.Siemens NX 10.0 is the basic platform of this project,which is developed with C + +language through NX/open,Ufun and DFA interfaces.Knowledge fusion knowledge engineering technology is integrated to realize the automatic updating mechanism of complex parametric surface model.At the same time,the parallel modeling strategy based on rib combination can not only reduce the complexity and development risk,but also help to realize the parallelization of module development,and significantly improve the development efficiency of software products.In a word,computers are machines whose capabilities are limited to low-level judgments based on calculations and assertions.For complex geometric model,it is unrealistic to transplant the engineer's modeling ideas to the computer.Therefore,it is necessary to develop a set of special modeling methods for the computer.This is the basic idea and innovation of this paper,and the final development results verify the value of this idea again.This value is not only reflected in the automatic design project of the hood inner panel,but also has reference significance for the design of other complex body structure parts.