Rapid Springback Compensation for Age Forming Based on Quasi Newton Method

来源 :Chinese Journal of Mechanical Engineering | 被引量 : 0次 | 上传用户:kollisjordan
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Iterative methods based on finite element simulation are effective approaches to design mold shape to compensate springback in sheet metal forming.However,convergence rate of iterative methods is difficult to improve greatly.To increase the springback compensate speed of designing age forming mold,process of calculating springback for a certain mold with finite element method is analyzed.Springback compensation is abstracted as finding a solution for a set of nonlinear functions and a springback compensation algorithm is presented on the basis of quasi Newton method.The accuracy of algorithm is verified by developing an ABAQUS secondary development program with MATLAB.Three rectangular integrated panels of dimensions 710 mm′750 mm integrated panels with intersected ribs of 10 mm are selected to perform case studies.The algorithm is used to compute mold contours for the panels with cylinder,sphere and saddle contours respectively and it takes 57%,22%and 33%iterations as compared to that of displacement adjustment(DA)method.At the end of iterations,maximum deviations on the three panels are 0.618 4 mm,0.624 1 mm and 0.342 0 mm that are smaller than the deviations determined by DA method(0.740 8 mm,0.740 8 mm and 0.713 7 mm respectively).In following experimental verification,mold contour for another integrated panel with 400 mm×380 mm size is designed by the algorithm.Then the panel is age formed in an autoclave and measured by a three dimensional digital measurement devise.Deviation between measuring results and the panel’s design contour is less than 1 mm.Finally,the iterations with different mesh sizes(40 mm,35mm,30 mm,25 mm,20 mm)in finite element models are compared and found no considerable difference.Another possible compensation method,Broyden-Fletcher-Shanmo method,is also presented based on the solving nonlinear functions idea.The Broyden-Fletcher-Shanmo method is employed to compute mold contour for the second panel.It only takes 50%iterations compared to that of DA.The proposed method can serve a faster mold contour compensation method for sheet metal forming. Iterative methods based on finite element simulation are effective approaches to design mold shapes to compensate springback in sheet metal forming. However, convergence rate of iterative methods is difficult to improve greatly. To increase the springback compensate speed of designing age forming mold, process of calculating springback for a certain mold with finite element method is analyzed. Springback compensation is abstracted as finding a solution for a set of nonlinear functions and a springback compensation algorithm is presented on the basis of quasi Newton method. accuracy of algorithm is verified by developing an ABAQUS secondary development program with MATLAB. Threed rectangular integrated panels of dimensions 710 mm’750 mm integrated panels with intersected ribs of 10 mm are selected to perform case studies. Algorithm is used to compute mold contours for the panels with cylinder, sphere and saddle contours respectively and it takes 57%, 22% and 33% iterations as compared to th at of displacement adjustment (DA) method. At the end of iterations, maximum deviations on the three panels are 0.618 4 mm, 0.624 1 mm and 0.342 0 mm that are smaller than the deviations determined by DA method (0.740 8 mm, 0.740 8 mm and 0.713 7 mm respectively). In following experimental verification, the mold contour for another integrated panel with 400 mm × 380 mm size is designed by the algorithm. The panel is age formed in an autoclave and measured by a three dimensional digital measurement devise .Deviation between measuring results and the panel’s contour is less than 1 mm. Finally, the iterations with different mesh sizes (40 mm, 35 mm, 30 mm, 25 mm, 20 mm) in finite element models are compared and found no substantial difference .Another possible compensation method, Broyden-Fletcher-Shanmo method, is also based on solving nonlinear functions idea. The Broyden-Fletcher-Shanmo method is employed to compute a mold contour for the second panel. Only only takes 50% iterations compared to to that of DA. The proposed method can serve a faster mold contour compensation method for sheet metal forming.
其他文献
The current research of configurable product disassemblability focuses on disassemblability evaluation and disassembly sequence planning.Little work has been do
崔维新(Wayson Choy)是当代知名的加拿大华裔作家,被称为“加拿大最有讲故事天赋的人”。作为土生华裔,他自幼在温哥华唐人街的生活经历,赋予其无限的创作素材、文学灵感和作家的
The current research of machine center accuracy in workspace mainly focuses on the poor geometric error subjected to thermal and gravity load while in operation
在中央“一带一路”战略的指引下,我国越来越多的施工企业开始走出国门参与到各国建设领域的竞争中.在国际工程承包市场的竞争不仅仅是施工技术、 施工标准、 成本控制的竞争
本文通过对荣华二采区10
房地产企业在国民经济的发展中起着重要作用,其所得税也成为国家财政收入的重要来源之一.房地产企业具有投资金额大、 经营周期长、 存在涉税问题多的问题.因此,如何加强对房
当今互联网、 云计算的不断发展,大数据扮演的角色的重要性越来越强,大数据时代对企业会计信息的提高有着积极的作用.全文主要采用了文献研究方法,对大数据和会计信息质量进
Structure design and fabricating methods of three-dimensional(3D)artificial spherical compound eyes have been researched by many scholars.Micro-nano optical man