Investigation on manufacturing and low-velocity impact performance of all-composite sandwich structure with S-type foldcore

A novel all-composite sandwich structure with S-type composite foldcore was designed and fabricated using an improved hot-press molding. Low-velocity impact tests with varying impact locations named Node-impact and Base-impact on the sandwich structure were performed via an Instron CEAST 9350 impacting machine. Experimental results showed two peaks exhibited on the histories of impact loads, where the peak value for Node-impact was larger than that of Base-impact at equal impact energy. Impact position possesses a significant influence on the impact resistance and damage mode of the composite structure. The sandwich structure achieved better impact resistance at Node-impact than Base-impact due to the strengthening of S-type composite foldcore. A user defined three-dimensional progressive damage mode was developed to predict the constitution and damage evolution of glass/epoxy fabrics, including fiber damage, matrix damage and interlaminar delamination. The predicted dynamic response and failure behavior of composite sandwich specimen agreed with experimental results.

Automated summary

A novel all-composite sandwich structure with S-type composite foldcore was designed and fabricated. Impact tests were conducted on the sandwich structure with varying impact locations. The results showed that impact position had a significant influence on the impact resistance and damage mode. A three-dimensional progressive damage mode was developed to predict the damage evolution of the composite structure, which agreed well with experimental results.