外文翻譯--cadcaecam在提高快速成形系統(tǒng)中的綜合應(yīng)用（英文）

1、CAD/CAE/CAM integration for increasing the accuracy of mask rapid prototyping systemYou-Min Huang *, Hsiang-Yao LanDepartment of Mechanical Engineering, National Taiwan University of Science and Technology, 43 Keelung Ro

2、ad, Section 4, Taipei 106, TaiwanReceived 5 July 2004; accepted 13 January 2005 Available online 17 March 2005AbstractsStereolithography is a rapid prototyping (RP) process that uses photopolymers as the raw materials fr

3、om which the prototypes are built. The photo-polymeric RP system uses lasers or other light sources to expose selectively the surface of the liquid resin. The absorption of energy causes photo-polymerization that changes

4、 the liquid resin into a solid, expanding the cured volume expanding but shrinking simultaneously. The volume shrinkage and curl distortion of the resin during photo- polymerization are the main reasons for the poor accu

5、racy of the built prototype, especially when the part is hollow, in which case the bending is greater because of the bending stress and cannot be compensated for. Normally, a designer builds a support in this stage to li

6、mit the further bending and deformation of the prototype. However, after the support has been removed from the built prototype, the geometric profile is easily damaged and deformed, so time is wasted. This study initiall

7、y uses dynamic finite element simulation code to simulate photo-polymerization, to determine the distortion of the outer profile of the part and thus reduce the deformation. Then, a reverse distortion correction is appli

8、ed to the outer profile of the part. A new reverse compensation CAD model is produced and loaded into a RP machine for practical prototype processing, to increase the accuracy of the process. Finally, the ‘‘H-4’’ diagnos

9、tic part is used as an example to verify the experimental results. The results of the simulation and experiment on the final after compensation were accurate. # 2005 Elsevier B.V. All rights reserved.Keywords: Computer-a

10、ided engineering; Stereolithography; Rapid prototyping; Finite element method; Curl distortion1. IntroductionIndustrial competition has accelerated the devel- opment of rapid prototyping (RP) systems. The use ofrapid pro

11、totyping systems can accelerate R fax: +886 2 2737 6460. E-mail addresses: ymhuang@mail.ntust.edu.tw (Y.-M. Huang), lanhf.hy@msa.hinet.net (H.-Y. Lan).0166-3615/$ – see front matter # 2005 Elsevier B.V. All rights reserv

12、ed. doi:10.1016/j.compind.2005.01.002and Jiang [8,9] used the dynamic finite element method (DFEM) to simulate stereolithography, based on the dynamic properties of photo-polymerization. Many of these studies have focuse

13、d on analyzing the effect of curing during build-up. However, only a few studies have sought to improve curl distortion, especially when the built part is hollow; this bending is very obvious and cannot be compensated by

14、 bending stress. This study presents verification and validation methods to improve the curl distortion using low-cost equipment. First, The equation based on DFEM theory [8,9], is used herein in numerical simulation wit

15、h input parameters that correspond to a practical processes. Then, the distortion of the built parts is predicted.Second, reverse distortion compensation is used to produce a new CAD model that is based on the predicted

16、distortion. Thirdly, the new CAD model is converted into a stereolithographic (STL) file. Finally, this new STL file is sent to a RP machine for further processing. Accordingly, the low-cost machines greatly improve the

17、accuracy of the part. The final results of the simulation and experiment are com- pared. Fig. 1 shows a flowchart of this process.2. Numerical analysisA modified mathematical model is proposed, based on the aforementione