Abstract:
This study presents an experimental study of the quasi-static axial compression and compression–compression fatigue
behavior of a three-dimensional braided carbon/epoxy composite tube. Three kinds of tubes with different braiding
angles, i.e. 25º, 35º, and 45º were used to examine the dependence of fatigue behavior on the braiding parameters.
Quasi-static compression and compression–compression cyclic loadings were carried out on the braided composite
samples. The S–N [stress and number of cycles to failure] curves, strain–N (number) curves, and damage observation
were used to evaluate the behavior of the braided tubes under fatigue loading. The test results showed that braiding
angle had significant effect on the ultimate compression strength (UCS) and the number of cycles per stress level that
the sample could withstand. The tube with 25º braiding angle had the highest UCS while the tube with 45º braiding
angle accumulates high number of cycles for the same stress level as compared to other samples. Damage occurred
along the braid angle for 25º tubes while matrix crack plus bulging occurred in the tubes with 35º and 45º braiding
angles.