Low‐velocity impact responses of polymethacrylimide foam–reinforced all‐composite Kagome honeycomb sandwich structures.

This article reports a carbon fiber–reinforced plastic Kagome composite honeycomb sandwich structure reinforced with polymethacrylimide (PMI) foam (PKCSS). Low‐velocity impact performances on the node, rib, and two cell centers of the PKCSS were experimentally compared with those on a composite Kagome honeycomb sandwich (CKHS), and the failure mechanism of the PKCSS was investigated. The impact process was analyzed through an explicit numerical analysis using ABAQUS. A three‐dimensional Hashin failure criterion was introduced using the VUMAT subroutine. Results confirmed that the PKCSS exhibits higher impact and specific loads than the CKHS, with the maximum improvements of 69.7% and 39.5%, respectively, under 50‐J impact energy. As an uncrushable material, the PMI foam provides strong impact resistance during its plateau stage. This technology of cell filling can be used to fabricate lightweight all‐composite honeycomb sandwiches for potential use in ultrahigh engineering applications. Highlights: Cell filling is applied in an all‐composite Kagome honeycomb sandwich.The LVI performances of the PKCSS and CKHS are experimentally compared.C‐scanning is used to analyze the failure of the considered structures.The PKCSS's numerical model is established to investigate the impact process.The enhancement mechanism of the PMI foam is analyzed. [ABSTRACT FROM AUTHOR]