Damage Assessment of 3-D Printed Ceramic Sandwich Structures with an Auxetic Honeycomb Core Subjected to Quasistatic Indentation Loading

Ceramic sandwich structures (CSS) have become an important material in the aerospace industry because of their high strength and excellent thermal insulation properties. However, the brittle nature of ceramic makes them vulnerable to damage from foreign objects, which can reduce their load-bearing capacity. In this paper, a series of tests were designed to investigate the response of CSS to impacts from foreign objects. To realize the damage characteristics and failure modes under the indentation force, a quasistatic indentation (QSI) test was conducted on CSS. Additionally, an acoustic emission device was used to capture damage signals during the QSI testing. Thereafter the extent of damage was evaluated by analyzing the damaged area and the compression after indentation properties. The results of these tests revealed the failure mechanism maps and indicated that the compressive strength of the damaged CSS had a stronger correlation with damage to the honeycomb core than to the face sheet.