Deformation path and springback behavior in double-curved bending at high temperature

다국어 초록 (Multilingual Abstract)

In this work, integrated double-curved bending–sizing–unloading is simulated for a Ti6Al4V titanium alloy sheet. Bending radii R30 mm × R30 mm and R30 mm × R15 mm are used in the bending tests at 700 °C and 750 °C, respectively. A holding time of 0–600 s is applied to explore the effect of sizing time on forming accuracy. Similar experimental tests are performed for comparison with the finite element analysis results. Results show that bending behavior varies remarkably with the bidirectional radii. As for equal bidirectional curvature, bending along each direction occurs simultaneously. Given that bidirectional radii are different, the sheet consecutively experiences single small-, single large-, and double-curved bending. The deformation path results in nonuniform plastic strain distribution. The springback amount increases from the center to the marginal middle zone. Sizing at 700 °C or 750 °C in 600 s or 180–600 s can remarkably reduce the springback amount, respectively. The springback prediction via finite element method is consistent with that of the experiment.

참고문헌 (Reference)

1 N. K. Sinha, "Viscous and delayed-elastic deformation during primary creep-using strain relaxation and recovery test" 48 : 1507-1512, 2003

2 E. -L. Odenberger, "Tool development based on modelling and simulation of hot sheet metal forming of Ti–6Al–4V titanium alloy" 211 (211): 1324-1335, 2011

3 P. Xue, "Theoretical prediction of the springback of metal sheets after a double-curvature forming operation" 89-90 : 65-71, 1999

4 Xiaohan Tang, "Strain rate dependent behaviors of a hot isotropically processed Ti-6Al-4V: Mechanisms and material model" 대한기계학회 30 (30): 661-665, 2016

5 T. X. Yu, "Stamping rectangular plates into doubly-curved dies" 198 (198): 709-125, 1984

6 J. Liao, "Springback reduction of a blade part using measuring based compensation methodology" 81 (81): 749-752, 2010

7 Y. J. Liu, "Research on the process of flexible blank holder in multi-point forming for spherical surface parts" 89 : 2315-2322, 2017

8 P. Liu, "Relationship between constant-load creep, decreasing-load creep and stress relaxation of titanium alloy" 638 : 106-113, 2015

9 W. S. Lee, "Plastic deformation and fracture behaviour of Ti-6Al-4Valloy loaded with high strain rate under various temperatures" 241 : 48-59, 1998

10 F. Barlat, "Plane stress yield function for aluminum alloy sheets-Part 1 : Theory" 19 : 1297-1319, 2003

11 D. H. He, "Optimization on springback reduction in cold stretch forming of titanium alloy aircraft ski" 20 : 2350-2357, 2010

12 Q. A. Tai, "On the measurement of friction coefficient of Ti-6Al-4V titanium alloy utilizing the hot compression test of ring and FE simulation" 6 : 21-31, 2011

13 N. Asnafi, "On springback of double-curved autobody panels" 43 : 5-37, 2001

14 D. Guines, "Numerical modeling of integrally stiffened structures forming from creep age forming technique" 1 : 1071-1074, 2008

15 김우곤, "Non-linear modeling of stress relaxation curves for Grade 91 steel" 대한기계학회 32 (32): 1143-1151, 2018

16 R. Boyer, "Materials Properties Handbook: Titanium Alloys, Technical note 5A, Superplastic Forming of Titanium Alloys"

17 R. Boyer, "Materials Properties Handbook: Titanium Alloys"

18 심도식, "Investigation of Tension Force in Stretch Forming of Doubly Curved Aluminum Alloy (Al5083) Sheet" 한국정밀공학회 17 (17): 433-444, 2016

19 M. H. Parsa, "Investigating spring back phenomena in double curved sheet metals forming" 41 : 326-337, 2012

20 K. Heung, "FEM-based optimum design of multi-stage deep drawing process of molybdenum sheet" 184 (184): 354-362, 2007

21 Y. Yan, "FEM modelling for press bend forming of doubly curved integrally stiffened aircraft panel" 22 : s39-, 2012

22 U. Borah, "Estimation of springback in doublecurvature forming of plates : Experimental evaluation and process modeling" 50 : 704-718, 2008

23 E. N. Chumachenko, "Development of computer simulation of industrial superplastic sheet forming" 499 : 342-346, 2009

24 J. Zhang, "Creep age forming of 2124 aluminum alloy with single/double curvature" 23 : 1922-1929, 2013

25 W. L. Hu, "An experimental study of the roll-bending of double-curvature workpieces" 55 : 28-32, 1995

26 L. Li, "An experimental study of the lubrication behavior of graphite in hot compression tests of Ti-6Al-4V alloy" 112 (112): 1-5, 2001

27 J. Liao, "A new springback compensation method for sheet metal bending based on curvature correction" v97-101 : 130-134, 2010