Impact compression characteristics and failure mechanism of 3D five-directional braided composites

Abstract

The dynamic compressive properties of 3D five-directional braided composites were investigated by using the Split Hopkinson pressure bar (SHPB) and the high-speed photography device. Through the impact compressive tests along the longitudinal and transverse directions of the sample with the braided angle of 22.3°, the stress-strain curves within the range of 200~1200/s strain rate were obtained respectively. And combined with the dynamic compressive process, the progressive failure law of the materials under high-speed deformation under different strain rates were analyzed. Meanwhile, the failure mode and failure mechanism of the material were further analyzed by combing the macroscopic failure characteristics and microscopic fracture morphology characteristics of the sample. The results show that the material is sensitive to strain rate in both longitudinal and transverse directions, among which the strain rate strengthening effect in transverse directions is more significant. The progressive failure process, stress-strain curve characteristics and the failure modes of the material under different loading directions are obviously different, and change with the increase of strain rate.

Keywords

• braided composites
• split hopkinson pressure bar
• dynamic compressive properties
• progressive failure process
• failure mode