Failure mechanism analysis of different types of manufacture for composite stiffened panels under axial compression load

In order to research the failure mechanism of secondary bonding and co-curing stiffened panels under axial compression load, test and numerical calculation were conducted for different types of manufacture of composite stiffened panels with edge constraint. In the test, strain gage was pasted to timely monitor the local buckling, while the load corresponding to initial acoustic emission was detected and fracture cross-section was observed to investigate the fracture mechanism. Based on the ABAQUS software, a finite element was observed to simulate the post-buckling-progress and damage progress. The calculated results are coordinated with the tested results very well. The results indicate that manufacture has no impact on the stability and load capacity, while the structure types have significant influence. Polymethacrylimide (PMI) foam can delay the occurrence of initial damage, even though it cannot increase the buckling load and ultimate load of panels. Initial damage of interface of secondary bonding panels occurs at a time close to fracture, while that of co-curing panels occurs early and extends slowly, so co-curing panels show better behavior of damage resistance.