دانلود رایگان مقاله درخت محور میانی ساختار پشتیبانی داخلی برای چاپ سه بعدی

Abstract

Saving material and improving strength are two important but conflicting requirements in 3D printing. We propose a novel method for designing the internal supporting frame structures of 3D objects based on their medial axis such that the objects are fabricated with minimal amount of material but can still withstand specified external load. Our method is inspired by the observation that the medial axis, being the skeleton of an object, serves as a natural backbone structure of the object to improve its resistance to external loads. A hexagon-dominant framework beneath the boundary surface is constructed and a set of tree-like branching bars are designed to connect this framework to the medial axis. The internal supporting structure is further optimized to minimize the material cost subject to strength constraints. Models fabricated with our method are intended to withstand external loads from various directions, other than just from a particular direction as considered in some other existing methods. Experimental results show that our method is capable of processing various kinds of input models and producing stronger and lighter 3D printed objects than those produced with other existing methods.

Conclusions

In this paper we introduced a medial axis tree structure to create a strong and light-weight model for 3D printing. Our designed structure consists of three components: (1) the medial structure which is near the medial axis of the input object and serves as the foundation of the whole supporting structure, (2) the hexagon boundary framework which is beneath the boundary surface and helps to disperse external loads and to resist shape deformation and (3) tree-like connecting bars serves as intermediate elements. These three components work together as an integrated supporting system. Topology and volume optimization are carried out to further improve the design. A number of experiment results show the capability of our method. Compared with other existing methods, our designed structure can withstand external loads from various directions, and produce stronger and lighter 3D printed objects.