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Sheu (2004) has recently carried out a simulation,where the front end of the sheet was fixed and the tools wasmoved towards the sheet with a given speed law. Therefore, itappears that the way the sheet is advanced through the rollsis unlikely to be important for the simulation result as far asthe speed of sheet remains moderate. This allows to simplifyFig. 18 – Insignificant influence of forming speeds on theformation of profile (dynamic response shifted 250rightwards for clarity).the modelling and to save on computational effort, especiallyfor complex profile shapes.Notice that in the study of Brunet et al. (1996), a differencebetween the experimental data and the simulation results onthe roll-forming of a trapezoidal section was observed. Sincethe simulationwas performedwithout rotating rolls, the effectof rotating rolls was assumed to contribute to this difference.Our present results however clear out this assumption.4. ConclusionsThe present study confirms the potential of the finite elementapproach in the simulation of a cold roll-forming process. 3Dsimulations quantitatively reflect the tendency of the phys-ical experiments and it may be useful in the explanationof different phenomena observed in the roll-forming prac-tice.Useful information like the stress/strain distribution andthe final geometry after springback has been obtained throughthis type of analysis. Influence of different forming param-eters such as the forming speed, the material properties,and the friction coefficient has also been parametricallystudied. This leads to a better insight and a more efficientdesign for the complicated technological roll-forming pro-cess.AcknowledgementsThe support of the Walloon Region through grant PROINDURW4543, as well as the support of ARCELOR S.A. is gratefullyacknowledged.referencesBrunet, M., Lay, B., Pol, P., 1996. Computer aided design ofroll-forming of channel sections. J. Mater. Process. Technol.60, 209–214.Bui, Q.V., Papeleux, L., Ponthot, J.P., 2001. Numerical simulation ofspringback using enhanced assumed strain elements. J.Mater. Process. Technol. 113, 774–778.Chung, J., Hulbert, G., 1993. A time integration algorithm forstructural dynamics with improved numerical dissipations:the generalized- method. J. Appl. Mech. 60,371–375.Damm, K., 1989. Determination of longitudinal strains in rollforming of standard sections in a multi-stand machine.Dissertation. Institute for Production Technology, Universityof Sarmstadt, Germany (in German).Han, Z.W., Liu, C., Lu, W.P., Ren, L.Q., 2002. Simulation of amulti-stand roll-forming process for thick channel section. J.Mater. Process. Technol. 127, 382–387.Heislitz, F., Livatyali, H., Ahmetoglu, M.A., Kinzel, G.L., Altan, T.,1996. Simulation of roll forming process with the 3-D FEMcode PAM-STAMP. J. Mater. Process. Technol. 59,59–67.Hong, S., Lee, S., Kim, N., 2001. A parametric study on forminglength in roll forming. J. Mater. Process. Technol. 113,774–778.Kiuchi, M., 1973. Analytical study on cold roll forming process,Report of Inst. Ind. Sci. No. 23, University of Tokyo.
摘要冷弯成形技术采用3D有限元分析，将理论知识与由线向应变与位移轨迹得出的数值结果想比较，通过对参量的研究，了解到行业局限和产品质量加工硬指数的重要影响，相比较而言冷弯形成速度与弯道内侧表面的摩擦处于次要地位。
1.介绍
冷弯成形是一种生产某种型材的长的金属薄片产品的工业生产办法，在这个过程中，通过不断地碾压改变薄板的厚度，一片平面薄板被改变成要求的轮廓，并不需要过多的改变厚度。这种高速度的生产过程适合于生产长的薄板并且不需要通过手动来调节公差。因此，弯道成形大多被描述为弯曲度的变形，通过碾压而不断地改变源`自*751~文·论^文`网[www.751com.cn。变形包括横向和纵向的伸展以及修整。更重要的是，这是一项非常复杂的事情，因为截面在不断地变化，因此会有很多不合格品产生。由于很难控制大小所以产品品质并不直观体现在横切面以及纵向弯曲度的走样。如果滚轴用的太多，则弯曲度会比较平缓，不合格品便产生了。然而，由于经济的限制，减少滚轴的使用会降低整体的成本，所以有的人为了减少加工成本而不顾生产质量。