完整版毕业设计外文翻译9570963Word格式.docx

1、Chuantao （C.T.） WangGeneral Motors Corp. Manufacturing Engineering, Die Center, 2000 Centerpoint, Pontiac, MI 48341Abstract. In the past decade, sheet metal forming and die development transformed to a science-based and technology-driven engineering and manufacturing enterprise from a tryout-based c

2、raft. Stamping CAE, especially the sheet metal forming simulation, as one of the core components in digital die making and digital stamping, this . The stamping simulation technology and its industrial applications , die developments, die construction and tryout, and production stamping. The stampin

3、g CAE community of the stamping CAE technology and business demands opens even greater opportunities and challenges to stamping CAE community in the areas of： （1） continuously improving simulation accuracy, drastically reducing simulation time-in-system, and improving operationalability （friendlines

4、s）, （2） resolving those and skidimpact lines）, （3） resolving total manufacturability problems in line die operations including blanking, drawredraw, trimpiercing, and flanging, and （4） overcoming new problems in forming new sheet materials with new forming techniques. In this article, the author fir

5、st provides an overview of the stamping CAE technology adventures and achievements, and industrial applications in the past decade. Then the author presents a summary of increasing manufacturability needs from the formability to total quality and total manufacturability of sheet metal stampings. Fin

6、ally, the paper outlines the new needs and trends for continuous improvements and innovations to meet increasing challenges in line die formability and quality requirements in automotive stamping.INTRODUCTIONThe forming simulation-based stamping CAE technology and its industrial applications , die d

7、evelopments, die construction and tryout, and production stamping in the past decade1.Since the NumiSheet Conference started in 1991, stamping CAE community fundamental understanding of sheet metal formability, forming mechanics, numerical methods, but also the most significantly, the fruitful indus

8、trial applications in a wide range of business segments.The automotive die and stamping industry benefit most from the stamping CAE. The technology advancement speeds up a in automotive die development and stamping from a tryout-based craft to a science-based and technologydriven engineering and man

9、ufacturing enterprise.Stamping CAE, especially the sheet metal forming simulation, this transition 1.In General Motors, the stamping CAE technology extensively used in many ways to significantly impact on various business segments of vehicle and tooling development processes. The applications and be

10、nefits are summarized as following: Stamping CAE is used as a DFM tool （Design for Manufacturability） to assess and validate the product styling surface designs to ensures a manufacturable sheet product design for a good start of vehicle program. It is used as a die engineering tool in stamping line

11、 die developments to validate and reshape binder and addendum on every new line of dies （blanking, draw,trim, flanging, and springback resolutions）. It is used as a tryout tool to replace soft tools and associated tryouts and to shorten ） die tryout to significantly reduce die cost and lead-time. It

12、 is used as a production tool to provide production stamping conditions （bead specifications, lube, binder tonnage, press load, blank gaging, die surface relief,gripper locations for automation, etc.）. It is used as a problem solving tool for production trouble shooting to reproduce manufacturing pr

13、oblems, to identify the root causes and to provide solutions for process control improvements. It is used as a simulation-based manufacturing guide to use the CAE output to drive consistency among die engineering, die construction, and production stamping. Finally, the stamping CAE is used as a lear

14、ning tool to explore and gain new knowledge and application guidance for new forming techniques （tubesheet applications just a few short years.As more stamping CAE application domains are explored, the more technical limitations and inadequacies are discovered. In turn, there come application-driven

15、 technology development and advancement. In this paper, the author reviews the evolutions of stamping CAE technology and its industrial applications in automotive product design, die development and production stamping. The industrial needs for technology improvements are described. The limitations

16、of current technology are identified and the needs for technology developments are reviewed.EVOLUTIONS OF STAMPING CAEStamping CAE technology development and industrial applications evolving in three main stages, namely, the fundamental research and lab work in 1970s-1980s, pioneer industrial trials

17、 in earlier 1990s, and the mass production applications after mid 1990s to 2000s.RESEARCH AND DEVELOPMENT （1970S-1980S）From 1970s to 1980s, the major developments were the fundamental studies of sheet forming mechanics, numerical modeling, and computational methods. The research work was primarily a

18、ccomplished in academia and research institutions.Reference 3 provides a comprehensive review of the research work during that period. The research topics were concentrated on numerical formulations such as membrane vs. shell, static implicit vs. Dynamic explicit）, toolsheet contact, material modeli

19、ng （yield functions, work early 1990s, the sheet forming industry, especially the automotive stamping, attempted the numerical simulations for large and complicated body panels. The Big 3s in Detroit led the world in this endeavor by developing their proprietary simulationtools for large 3-dimension

20、al problems. Stoughton 8 of General Motors developed PanelForm combining automatic mesh generation with membrane formulation based on earlier work of Wang did when same time, Wang led theChrysler group developed C-Form and Tang in Ford Motor developed MetalForm, and both codes were based on shell fo

21、rmulation with static and implicit solvers. Other groups including the commercial software vendors also developed the industrialoriented software, noticeably, Pamstamp from ESI （Engineering Systems International） of France, LSDyna3d from LSTC （Livermore Software Technology Co.）, both codes are based

22、 on shell formulation and dynamic explicit solver, and both Pamstamp and LSDyna3D Dyna3D, a public domain code from Livermore Laboratory, a USA government funded research institution. The professional conferences in numerical simulations of metal forming process in earlier 1990s, especially the Numi

23、Sheet 13-17 and NumiForm 18-25 greatly improved our understanding of all important aspects of finite element simulations of sheet metal forming. The NumiSheet Conferences provided comprehensive exams for the readiness of the simulation technology for industrial problems. The major difficulties and c

24、hallenges discovered for industrialization during that period were （1） finite element modeling （ robustness （ time （ tools （such as Pamstamp and LS-Dyna3D） with full shell formulations and dynamic implicit solvers. The finite element codes with one-step membrane formulation were also got attention o

25、f the industrial users for the capabilities of using the large number of finer elements and short computation time although the accuracy of the results was questionable.The economic down turns in USA in early 1990s and the recovery efforts by the automotive industry, especially General Motors North

26、American Operations, pushed the applications of math-based tools and process in design, engineering and manufacturing. By the mid of 1990s, the stamping CAE emerged as new engineering field in die and sheet metal forming industry. A new profession stamping CAE engineer, created since then.The NumiSh

27、eet 1996 Dearborn Michigan marked the beginning of mass production applications of stamping simulations worldwide 15. In 1996, after three year intense integrated technology development and productionization, GM North American Stamping completed its in applying simulation based digital validations f

28、or all draw dies engineered and constructed in 1990s, the industrial applications of stamping CAE technology were mainly focused on forming simulations for draw die that is the one of the line dies needed to form an automotive panel. The stamping CAE community mainly focused on predicting the tradit

29、ional formability problems （splits and excessive thinning, wrinkles）. GM predicting formability problems with very draw die forming. Fig. 1 illustrates excellent correlations between predictions and measurements for an aluminum decklid. The thinning was measured very precisely using the pinpoint mic

30、ron meter at the same locations identified in simulations, and the surface strains were measured by conventional circle grids that normally bands. The thinning correlation is excellent, and the predicted major andminor strains are within the measurement bands. FIGURE 1. Thinning and strains measurem

31、entsThinning FIGURE 2. Thinning comparisonMajor StrainFIGURE 3. Major strain comparisonMinor StrainFIGURE 4. Minor strain comparisonMASS PRODUCTION APPLICATIONS AND CHALLENGES （2000s）In todays die and stamping industry, the stamping CAE for digital validations of die developments before production t

32、rials is a critical business for lead-time reduction,cost reduction and quality improvements.The industry and CAE engineers push the technology envelop limit and attempt to apply the simulations to almost all possible areas of sheet metal forming to maximize the power of simulation and its financial benefits. In the automotive stamping are summarized as following. Increasing part size and shape complexity such as whole body side panels, and multiple attac