Evaluation of rods deformation of metal lattice structure in additive manufacturing based on skeleton extraction technology

Abstract

The components with lattice structure as filling unit have great application potential in aerospace and other fields. The failure of the lattice structure directly affects the functional characteristics of the parts filled with the lattice structure. Aiming at the problem that it is difficult to evaluate the deformation degree of metal lattice structure after mechanical loading in additive manufacturing, firstly, the point cloud model of lattice structure is obtained by using CT scanning and three-dimensional reconstruction, and then the skeleton of lattice structure is automatically extracted based on ${L_1}$ median algorithm. Finally, the deformation angle of rods is measured to evaluate the degree of deformation and damage of parts. In this paper, the deformation evaluation of the rods of the BCC lattice is discussed. The experimental results show that the proposed skeleton extraction technology achieves the evaluation of lattice structure deformation. The experimental model is extended to BCC lattice structure with unit cell number of $n \times n \times n$. When the ratio of the rods with more than 40% severe deformation to all rods in the lattice structure reaches $(2n - 1)/2{n^2}$ it indicates that the lattice structure has undergone a large degree of deformation and should not continue to serve.

Keywords

• additive manufacturing
• bcc lattice structure
• skeleton extraction
• l1 median value
• rods deformation
• deformation detection