Abstract: In order to obtain the material-saving effect and optimized physical and mechanical properties of 3D printing models, starting with the lattice shape variability, a lattice-based 3D printing lightweight structure generation method was proposed. The resulting lightweight structure was employed to replace the solid space of the given model. Firstly, a general unit cell description method was proposed to design the geometric and topological characteristics of unit cell. Secondly, the topology skeleton structure, on which the solid modeling was based, was constructed by periodically arranging lattice units in the bounding box of the model. Finally, a geometric modeling method based on mesh splicing was utilized to directly construct the STL model, and the lattice solid structure with controllable mesh quality can be obtained quickly without Boolean operation. The 3D printing molding process suitable for lattice structure was verified through object printing. Comparisons and analyses were conducted on the geometrical and mechanical properties of the five kinds of typical lattices serving as a preliminary basis for lattice design and selection. The examples show that this method can not only save material and improve the strength-weight ratio of the model, but also guarantee the printability, self-balancing, and the optimization of mechanical properties of the lightweight model. Compared with previous methods, it is advantageous in variability and efficiency and is applicable to various engineering applications. 

Key words:  , 3D printing, lightweight model, periodic lattice, solid modeling, object printing