Damage evolution and failure mechanism of carbon fiber wound composite tubes under lateral compression

Carbon fiber winding composite tubes are widely used in automobiles, pressure vessels, and other structures because of their excellent performance. The difference in fiber winding angle has a significant impact on the performance of carbon fiber winding composite tubes. In this study, the effect of different winding angles (+/- 35 degrees, +/- 55 degrees, and +/- 75 degrees) on the transverse compressive strength of carbon fiber winding tubes was studied by acoustic emission and high-speed photography. The mechanical properties and damage evolution during compression were investigated by analyzing the multifractal properties and sentinel functions of acoustic emission (AE) signals. The results show that increasing the winding angle can improve the load-carrying capacity. The peak load of the +/- 75 degrees tube is 123.5% higher than that of the +/- 35 degrees tube and 14.6% higher than that of the +/- 55 degrees tube. In all samples, matrix cracking was the dominant damage mode, accounting for more than 90%, followed by delamination and fiber breakage. Scanning electron microscopy revealed fracture patterns on the outer surface for different winding angles. In addition, the winding angle plays an important role in the stiffness and surface damage morphology of the tube.Highlights Effect of winding angle on lateral compression of CFRP tube. AE and high-speed camera reveal the damage process. Multifractal features and sentry function can reveal the damage evolution process. The winding angle significantly impacts tube outer surface fracture patterns.