Effects of the internal pressure and stacking sequence on the transverse impact behavior of hybrid uniaxial-biaxial braided composite tubes

Abstract

In this paper, the response of hybrid uniaxial and biaxial braided composite tubes subjected to transverse low-velocity impact under internal pressure load is studied experimentally. Two groups of specimens without internal pressure (0 MPa) and with internal pressure (2 MPa) are set up for low-velocity impact test, and the energy is set to 10 J, 20 J and 30 J. The Micro-CT damage reconstruction is performed to evaluate the impact damage mechanisms of hybrid tubes. The results show that the impact resistance of structural hybrid specimens is better than that of pure uniaxial and biaxial braided specimens. The position of biaxial braided layer is the main factor to distinguish the performance of hybrid composite tubes. Based on the characteristics of yarn interlacing, when the biaxial braided layer is arranged in the outermost layer, the intralaminar crack propagation is inhibited to protect the surface of the specimen. The damage area is dispersed to reduce the stress concentration, while it is placed in the innermost layer. The existence of internal pressure mainly affects the distribution and degree of yarn damage, which can significantly improve the impact resistance of tubes.