An automatic optimization method for minimizing supporting structures in additive manufacturing

Abstract

The amount of supporting structure usage has been a major research topic in layer-based additive manufacturing (AM) over the past years as it leads to increased fabrication time and decreased surface quality. Previous studies focused on deformation and topology optimization to eliminate the number of support structures. However, during the actual fabrication process, the properties of shape and topology are essential. Therefore, they should not be modified casually. In this study, we present an optimizer that reduces the number of supporting structures by identifying the prime printing direction. Without rotation, models are projected in each direction in space, and the basis units involved in the generation of support structures are separated. Furthermore, the area of the supporting structures is calculated. Eventually, the prime printing direction with minimal supporting area is obtained through pattern-searching method. The results of the experiment demonstrated that the printing area was reduced by up to 60% for some cases, and the surface quality was also improved correspondingly. Furthermore, both the material consumption and fabrication time were decreased in most cases. In future work, additional factors will be considered, such as the height of the supporting structures and the adhesion locations to improve the efficiency of this optimizer.

Keywords

Printing direction / Optimization / Supporting structures

References

[1] Cunico MWM. Development of new rapid prototyping process. Rapid Prototyp J, 2011, 17: 138-147.

[2] Jin Y, He Y. Optimization of tool-path generation for material extrusion-based additive manufacturing technology. Addit Manuf, 2014, 1/4: 32-47.

[3] Pereira S, Vaz AIF, Vicente LN. On the optimal object orientation in additive manufacturing. Int J Adv Manuf Technol, 2018, 98: 1685-1694.

[4] Cheng W, Fuh JYH, Nee AYC, et al. Multi-objective optimization of part building orientation in stereolithography. Rapid Prototyp J, 1995, 1(4): 12-23.

[5] Hu K, Jin S, Wang CCL. Supporting slimming for single material based additive manufacturing. Comput Aided Des, 2015, 65: 1-10.

[6] Jiang J, Xu X, Stringer J. Support structures for additive manufacturing: a review. J Manuf Mater Process, 2018, 2(4): 64

[7] Tay YWD, Li MY, Tan MJ. Effect of printing parameters in 3D concrete printing: printing region and support structures. J Mater Process Technol, 2019, 271: 261-270.

[8] Gao W. The status, challenges, and future of additive manufacturing in engineering. Comput Aided Des, 2015, 69: 65-89.

[9] Stava O, Vanek J, Benes B. Stress relief: improving structural strength of 3D printable objects. ACM Trans Graph, 2012, 31(4): 1-11.

[10] Luo L, Baran I, Rusinkiewicz S, et al. Chopper: partitioning models into 3D-printable parts. ACM Trans Graph, 2012, 31(6): 1-9.

[11] Chen D, Levin D, Didyk P, et al. Spec2Fab: a reducer-tuner model for translating specifi cations to 3D prints. ACM Trans Graph, 2013, 32(4): 1-9.

[12] Paul R, Anand S. Optimization of layered manufacturing process for reducing form errors with minimal support structures. J Manuf Syst, 2015, 35: 231-243.

[13] Leary M, Merli L, Torti F, et al. Optimal topology for additive manufacture: a method for enabling additive manufacture of support-free optimal structures. Mater Des, 2014, 63: 678-690.

[14] Prévost R, Whiting E, Lefebvre S, et al. Make it stand: balancing shapes for 3D fabrication. ACM Trans Graph, 2013, 32(4): 1-10.

[15] Wang W, Wang TY, Yang Z, et al. Cost-effective printing of 3D objects with skin-frame structures. ACM Trans Graph, 2013, 32(6): 1-10.

[16] Chen Y. Determining parting direction based on minimum bounding box and fuzzy logics. Int J Mach Tools Manuf, 1997, 37(9): 1189-1199.

[17] Priyadarshi AK, Gupta SK. Finding mold-piece regions using computer graphics hardware. Lect Notes Comput Sci, 2006, 4077: 655-662.

[18] Khardekar R, Burton G, McMains S. Finding feasible mold parting directions using graphics hardware. Comput Aided Des, 2006, 38(4): 327-341.

[19] Li W, Martin R, Langbein FC. Molds for meshes: computing smooth parting lines and undercut removal. IEEE Trans Autom Sci Eng, 2009, 6(3): 423-432.

[20] Cheng B, Chou K. Geometric consideration of support structures in part overhang fabrications by electron beam additive manufacturing. Comput Aided Des, 2015, 69: 102-111.

[21] Giannitelli SM, Mozetic P, Trombetta M, et al. Combined additive manufacturing approaches in tissue engineering. Acta Biomater, 2015, 24: 1-11.

[22] Tyberg J, Bohn JH. FDM systems and local adaptive slicing. Mater Des, 1999, 20(2/3): 77-82.

[23] Huang P, Wang CCL, Chen Y. Algorithms for layered manufacturing in image space. Adv Comput Inf Eng Res, 2014, 1: 377-410.

[24] Chen Y, Li K, Qian X. Direct geometry processing for tele-fabrication. J Comput Inf Sci Eng, 2013, 13(4): 1-18.

Funding

National Key R&D Program of China(2017YFB1104100)

Science and Technology Commission of Shanghai Municipality http://dx.doi.org/10.13039/501100003399(16441908400)

Shanghai Jiao Tong University Foundation on Medical and Technological Joint Science Research(YG2016ZD01)

National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809(81828003)