Shell thickening for extrusion-based ceramics printing.

• We investigate the structural stability problem for shell models in extrusion-based ceramics 3D printing and explore the factors that cause instability or collapse during fabrication. • We introduce a lightweight structural analysis solver for the given shell model based on moment equilibrium instead of volumetric mesh-like finite element methods. The structural analysis considers the gravity and adhesion force during printing and provides the real-time visualization of stability distribution. • We propose a structural optimization algorithm based on local shell thickening that enhances the stability during fabrication and does not affect the object's exterior appearance, expanding the feasible shape space of shell structures fabricated by extrusion-based ceramics 3D printing. The algorithm works directly on the printing file and produces the new G-code commands. [Display omitted] Additive manufacturing of ceramics gains increasing attention in recent years, as ceramic material like clay processes distinctive merits, including hardness, thermal and chemical stability, etc. The customer-level extrusion-based ceramics 3D printer is getting easily achievable. However, due to its semi-liquid and highly viscoelastic properties, the clay material causes new challenges to the computational aspects. It does not dry instantly and may collapse during the accumulated force from new layers breaks the moment equilibrium, especially when adjacent layers have less overlap region. We tackle this unique problem, focusing on shell-like models in extrusion-based ceramics printing in this paper. We propose a structural analysis algorithm that considers the moment equilibrium for each layer along the fabrication process. We also present a computational framework to enhance the structural stability by local thickening of the shell models without affecting the appearance. We demonstrate the printing process and physical results to validate our method. [ABSTRACT FROM AUTHOR]