Abstract
•The usage of correlation between maximum temperature and peak load.•The reconstruction of CT images identifies the debonding distribution and degree.•A novel inspection way of combing infrared imaging and micro CT reconstruction methods.•The role of axial yarns in axial crushing.
In this work, the effect of axial yarns on damage behavior of two-dimensional triaxially braided composite(2DTBC) tubes subjected to axial compression was investigated. A novel damage detection method combining infrared thermography and CT scanning was presented. In the area without axial yarns, yarn crossovers were separated from each other due to interlacing patterns. Axial compression caused the braiding yarns to shear deformation like scissors. Inter-yarn de-bonding appeared in crossovers and could not connect. Consequently, it caused a progressively folding failure mode. In contrast, local buckling occurred on axial yarns because of their primary loading behavior. Cracks along the axial yarns formed, which would combine with debonding crossovers caused by the sheared braiding yarn. It resulted in significant inter-layer delamination and consequently splaying failure mode. The energy absorption of composites tube with 18 axial yarns increased by 79.9% at the cost of 27.8% fiber usage more than 3 axial yarns.