Abstract
Single point incremental forming (SPIF) is a relatively new manufacturing process that has been recently used to form medical grade titanium sheets for implant devices. However, one limitation of the SPIF process may be characterized by dimensional inaccuracies of the final part as compared with the original designed part model. Elimination of these inaccuracies is critical to forming medical implants to meet required tolerances. Prior work on accuracy characterization has shown that feature behavior is important in predicting accuracy. In this study, a set of basic geometric shapes consisting of ruled and freeform features were formed using SPIF to characterize the dimensional inaccuracies of grade 1 titanium sheet parts. Response surface functions using multivariate adaptive regression splines (MARS) are then generated to model the deviations at individual vertices of the STL model of the part as a function of geometric shape parameters such as curvature, depth, distance to feature borders, wall angle, etc. The generated response functions are further used to predict dimensional deviations in a specific clinical implant case where the curvatures in the part lie between that of ruled features and freeform features. It is shown that a mixed-MARS response surface model using a weighted average of the ruled and freeform surface models can be used for such a case to improve the mean prediction accuracy within ±0.5 mm. The predicted deviations show a reasonable match with the actual formed shape for the implant case and are used to generate optimized tool paths for minimized shape and dimensional inaccuracy. Further, an implant part is then made using the accuracy characterization functions for improved accuracy. The results show an improvement in shape and dimensional accuracy of incrementally formed titanium medical implants.
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Aydin S, Kucukyuruk B, Abuzayed B, Aydin S, Sanus GZ (2011) Cranioplasty: review of materials and techniques. J Neurosci Rural Pract 2(2):162–167
Duflou JR, Behera AK, Vanhove H, Bertol LS (2013) Manufacture of accurate titanium cranio-facial implants with high forming angle using single point incremental forming. Key Eng Mater 549:223–230
Göttmann A, Korinth M, Schäfer V, Araghi BT, Bambach M, Hirt G (2013) Manufacturing of individualized cranial implants using two point incremental sheet metal forming. In: Schuh G, Neugebauer R, Uhlmann E (eds) Future Trends in Production Engineering. Springer, Berlin Heidelberg, pp 287–295
Lu B, Ou H, Shi SQ, Long H, Chen J (2014) Titanium based cranial reconstruction using incremental sheet forming. Int J Mater Form (Flexible forming - Incremental Sheet Forming & Roll Forming): 1-10 doi: 10.1007/s12289-014-1205-8
Lu B, Xu DK, Liu RZ, Ou H, Long H, Chen J (2015) Cranial reconstruction using double side incremental forming. Key Eng Mater 639:535–542
Eksteen PD, Van der Merwe AF (2012) Incremental sheet forming (ISF) in the manufacturing of titanium based plate implants in the bio-medical sector. In: Proceedings of the International Conference on Computers & Industrial Engineering (CIE 42), Cape Town, South Africa, 2012. CIE & SAIIE 2012:569-575
Araujo R, Teixeira P, Montanari L, Reis A, Silva MB, Martins PA (2014) Single point incremental forming of a facial implant. Prosthetics Orthot Int 38(5):369–378
Ambrogio G, De Napoli L, Filice L, Gagliardi F, Muzzupappa M (2005) Application of incremental forming process for high customised medical product manufacturing. J Mater Process Technol 162–163:156–162
Behera AK (2013) Shape feature taxonomy development for toolpath optimisation in incremental sheet forming. PhD Thesis. Katholieke Universiteit Leuven. ISBN 978-94-6018-733-9
Jeswiet J, Micari F, Hirt G, Bramley A, Duflou J, Allwood J (2005) Asymmetric single point incremental forming of sheet metal. Cirp Ann-Manuf Techn 54(2):623–649
Duflou JR, Verbert J, Belkassem B, Gu J, Sol H, Henrard C, Habraken AM (2008) Process window enhancement for single point incremental forming through multi-step toolpaths. Cirp Ann-Manuf Techn 57(1):253–256
Skjødt M, Hancock MH, Bay N (2007) Creating helical tool paths for single point incremental forming. Key Eng Mat 344:583–590
Malhotra R, Reddy NV, Cao JA (2010) Automatic 3D spiral toolpath generation for single point incremental forming. J Manuf Sci E-T Asme 132(6):1–10. doi:10.1115/1.4002544
Hirt G, Ames J, Bambach M, Kopp R (2004) Forming strategies and process modelling for CNC incremental sheet forming. Cirp Ann-Manuf Techn 53(1):203–206
Li JC, Hu JB, Pan JJ, Geng P (2012) Thickness distribution and design of a multi-stage process for sheet metal incremental forming. Int J Adv Manuf Tech 62(9-12):981–988
Verbert J, Behera AK, Lauwers B, Duflou JR (2011) Multivariate adaptive regression splines as a tool to improve the accuracy of parts produced by FSPIF. Key Eng Mater 473:841–846
Khan MS, Coenen F, Dixon C, El-Salhi S, Penalva M, Rivero A (2015) An intelligent process model: predicting springback in single point incremental forming. Int J Adv Manuf Technol 76(9-12):2071–2082
Verbert J, Duflou JR, Lauwers B (2007) Feature based approach for increasing the accuracy of the SPIF process. Key Eng Mat 344:527–534
Behera AK, Gu J, Lauwers B, Duflou JR (2012) Influence of material properties on accuracy response surfaces in single point incremental forming. Key Eng Mater 504–506:919–924
Micari F, Ambrogio G, Filice L (2007) Shape and dimensional accuracy in single point incremental forming: state of the art and future trends. J Mater Process Technol 191(1-3):390–395
Essa K, Hartley P (2011) An assessment of various process strategies for improving precision in single point incremental forming. Int J Mater Form 4(4):401–412
Rauch M, Hascoet JY, Hamann JC, Plenel Y (2009) Tool path programming optimization for incremental sheet forming applications. Comput Aided Des 41(12):877–885
Lu B, Chen J, Ou H, Cao J (2013) Feature-based tool path generation approach for incremental sheet forming process. J Mater Process Technol 213(7):1221–1233
Samui P (2014) Determination of surface and hole quality in drilling of AISI D2 cold work tool steel using MPMR, MARS and LSSVM. J Adv Manuf Syst 13(04):237–246
Bentley JL (1990) KDTrees for semidynamic point sets. Proceedings of the Sixth Annual Symposium on Computational Geometry:ACM. New York, NY, USA:187-197
Behera AK, Verbert J, Lauwers B, Duflou JR (2013) Tool path compensation strategies for single point incremental sheet forming using multivariate adaptive regression splines. Comput Aided Des 45(3):575–590
Cohen-Steiner D, Morvan J-M (2003) Restricted Delaunay triangulations and normal cycle. In: Proceedings of the 19th Annual Symposium on Computational Geometry: ACM. New York, NY, USA:312-321
Alliez P, Cohen-Steiner D, Devillers O, Levy B, Desbrun M (2003) Anisotropic polygonal remeshing. ACM Trans Graph 22(3):485–493
Behera AK, Vanhove H, Lauwers B, Duflou JR (2011) Accuracy improvement in single point incremental forming through systematic study of feature interactions. Key Eng Mater 473:881–888
Behera AK, Lauwers B, Duflou JR (2014) Tool path generation framework for accurate manufacture of complex 3D sheet metal parts using single point incremental forming. Comput Ind 65(4):563–584
Behera AK, Lauwers B, Duflou JR (2014) Tool path generation for single point incremental forming using intelligent sequencing and multi-step mesh morphing techniques. Int J Mater Form (Advanced Modeling and Innovative Processes):1-16 doi: 10.1007/s12289-014-1174-y
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Behera, A.K., Lu, B. & Ou, H. Characterization of shape and dimensional accuracy of incrementally formed titanium sheet parts with intermediate curvatures between two feature types. Int J Adv Manuf Technol 83, 1099–1111 (2016). https://doi.org/10.1007/s00170-015-7649-2
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DOI: https://doi.org/10.1007/s00170-015-7649-2