Failure analysis of Al/CFRP hybrid tube with initial damage during axial compression

Abstract

Damage can limit the material and structure to perform as designed. To investigate the effect of damage present at the Al and carbon layers in Al/CFRP hybrid thin-walled tubes, a coupled model with multiple working conditions was developed. Material and structural changes caused by different damage levels were analyzed from macroscopic and microscopic perspectives using stereoscopic microscope and CT scanning techniques. Axial compression tests were performed to obtain the load–strain relationships to investigate the correlation between the mechanical properties of the hybrid tube and the damage level. Finally, the finite element method (FEM) is used to conduct coupled transverse–axial​ compression analysis, and the damage mechanism is revealed by extracting the stress triaxiality and damage parameters of the failure unit at typical locations in the Al layer; the damage evolution process of the layup angle is analyzed by plotting the analysis step time-damage percentage curve; the influence of the damage sprouting location on the load-bearing capacity of the hybrid tube is discussed by changing the location of the damage defect. In practice, it provides a theoretical reference for the design, production, processing, maintenance, and repair of hybrid tubes, and scientific and reasonable control of the damage that may exist during the service of the tubes.