Multi-scale numerical simulation of impact failure for cylindrical CFRP

In this study, we aimed to predict various impact failure behavior of cylindrical CFRPs with multiscale analyses using individual properties of fiber, interface, and resin including strain-rate dependence. We conducted compressive impact tests for the cylindrical CFRPs using split Hopkinson pressure bar (SHPB) method. Tests were carried out under four different compressive condition; radial direction and axial direction compressive tests for CFRP-H in which the fiber was aligned in the hoop direction and CFRP-L in which the fiber was aligned in the axial direction. Strengths in Hashin damage theory used in the macroscale analyses were determined by microscale analyses. Failure envelope in transverse direction and fiber-axial shear strength were obtained by 3D periodical unit cell analyses with considering the strain-rate dependence of resin strength. In addition, tensile and compressive strengths in fiber-axial direction were determined using the simultaneous fiber failure model and the fiber microbuckling model, respectively. Results of macroscale SHPB analyses were compared to test results. In terms of fracture process, analysis results did not match to test results because we conducted simulations without considering fracture energy. In terms of failure strength, failure load and failure occurred point, we could confirm rather good agreement between analysis results and test results.

Automated summary

This study aimed to predict impact failure behavior of cylindrical CFRPs using multiscale analyses with consideration of strain-rate dependence. While the fracture process analysis results did not match test results, there was good agreement between analysis results and test results in terms of failure strength, load, and failure point.