Compressive responses of ceramic lattices: Experiments and simulations

The strength of ceramic lattices is governed by their architecture, material defects, and geometrical imperfections. Most numerical models, however, incorporate only material defects or geometrical imperfections. Here, we introduce a modelling approach that combines both effects and is supported by experimental validation. Silica octet-truss lattices were fabricated by stereolithography with relative densities ranging from 9.5% to 33%. Computed tomography was used to quantify manufacturing imperfections, including non-uniform struts, material accumulation at the joints, and non-parallel surfaces. The scanned geometries were converted into finite element meshes, where each element was assigned a stochastic strength based on a Weibull distribution calibrated from separate tensile tests. The simulations successfully reproduced the progressive brittle fracture observed experimentally, including multiple load drops and the formation of a diagonal fracture plane. The results further showed that geometrical imperfections affect how the compressive strength scales with relative density, deviating from the expected stretching-dominated behavior. Overall, a very good agreement was obtained between experiments and simulations, demonstrating that accurately predicting the compressive response of ceramic lattices requires accounting for both geometrical imperfections and stochastic material strength.