Progressive failure analysis of anisogrid cylindrical composite lattice structure with manufacturing defects

This study performs a compression test of a cylindrical composite lattice structure and numerically investigates the failure process and behavior. Prior to the test and analysis, the distributions of the fiber tow, matrix, and manufacturing defects were observed and measured in cross-sectional images. A progressive failure analysis that considers different matrix pocket lengths and void contents was performed to examine the effects of manufacturing defects on the compressive strength. The intersecting fiber tow and matrix pocket was modeled using a continuum element and the geometry measured in the cross-sectional image. A cyclically symmetric boundary condition was applied to the symmetric model. Fracture energy-based damage evolution for the fiber tow and cohesive zone modeling for the interface failure were employed. The failure behaviors of the different damage models were compared, and the progressive failure analysis model was verified by comparing it with the test results. The results of the progressive failure analysis, considering manufacturing defects, were similar to the test results.