| Currently, China's automobile industry has gradually incorporated into the world automobile industry system in many aspects, such as manufacture, research and development, sales services, automobile credit etc. It accelerates the development of China's automobile industry and makes China become one of the major manufacturing bases. In the long term perspective, China's automobile industry will gain the ability of self-development and improve the status in the world automobile industry system.In the independent research and development of automobile, auto body is always the main factor in product quality and development cycle. The designers rarely consider the factor of auto panel formability during the early design stage. This is mainly because the technical factors in stamping are not complete during the early design stage of parts, which makes it impossible to calculate using the traditional analysis software based on incremental algorithms of FEM procedures. Furthermore, the solvers based on incremental algorithms have an advantage of high precision, but its calculation time is so long that the traditional simulation of auto panel can't satisfy the requirement of fast formability checking during the early design stage of automobile parts. In the past ten years, there has existed one-step inverse finite element method based on total deformation theory, the corresponding analysis software for stamping have succeed one after another and have been applied in actual production widely.The research of this paper is supported by the key project of National Automotive Electronic High-tech Industries"CAD/CAE/CAM software platform for digital auto body parts fine design and manufacturing"(SDRC high-tech 2042), the key project of National Outstanding Scientific Youth Funds"The CAD expert system theory based KBE of stamping design and the research on the polymer forming theory and calculation method"(10125208) and the sub-item of"985"project on Automotive Engineering Technology Innovation Platform"body design and manufacture of digital key technologies". The research contents of this paper are CAE software development platform for auto-body panel, some key algorithms of one-step inverse finite element method for auto-body parts, pre-processing system and post-processing system, and the corresponding software testing platform.Based on COMX technology, we first define the basic programming standard and API of software system, and then we design and implement the"Class Factory"component which is central part of the COMX platform. This component mainly handle the install/uninstall of other components, parse of xml configuration files, the creation and recycling of component objects, the garbage collection mechanism on component-level, and so on. According to the"Class Factory"mentioned above, we also make a further research on some basic and necessary components in the CAE software system for auto-body panel, it includes: (1) The key data structure component of the simulation of the Sheet Metal Forming, corresponding display component and serialization component; (2) Visualization components based on OpenGL, including render context component, pick-up component, light and material component, 3D transformation components, I/O component based on OpenGL and post-processing components, etc; (3) GUI components based on plug-in and the corresponding development tools, they includes: (a) the basic component which is used to load and manage GUI components; (b) the common progress bar component; (c)other basic tool components. The components above compose the basic development platform for common auto-body panel CAE analysis system, there are many successfully developed or being developed software modules, such as KMAS/One-step, KMAS/Incremental, KMAS/Mesher, and KMAS/UFT and so on. This paper will focus on the subsystem of One-step and developments of some key algorithms of it. The successful developments of these modules validate the expandability, reusability and portability of the COMX software development platform.Based on the COMX software development platform constructed before, this paper focuses on the design and implementation of the software system KMAS/One-step for the fast forming simulation of auto-body, and the in-depth study on some key algorithms in the software, they mainly include: (1)Initial field indication algorithm based on spring element energy release for One-step solver. Currently, some main initial field indication algorithms (e.g. projection method, ray method, section line method et al.) can't deal with the flange and concave issues, especially the latter one, or they can only solve the parts with specific geometry. But many parts have flange and concave issues in actual product process, if there is not any efficient and common initial field algorithm aiming at these problems, the application of One-step Solver would be limited to a very small range. We propose an improved dynamic explicit initial field indication algorithm based on spring element energy release, which can efficiently solve the issues mentioned above, and make One-step solver deal with the fast forming simulation questions of progressive die part and improve the availability of One-step solver. (2) As a software module for fast checking formability during the early design stage of parts, high demand in the solver efficiency are generally required by users. By the in-depth study of large-scale linear finite element sparse matrix, this paper introduces some more efficient solvers for solving the sparse matrixes and it improves the calculation speed of One-step solver greatly.(3)There are also some researches on key algorithms of pre-process and post-process modules of KMAS/One-step system, such as the application of contact judgment algorithm in solver and pre-/post-process, the checking and revising algorithms of meshes quality, etc. (4)Since testing is an indispensable stage during the industrialization for software from laboratories to factories, there exist also some related researches on the testing methods for One-step solver and the design and implementation of the automatically testing environment for the solver in this paper.
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