Mechanical Behavior Analysis of Composite Shell with Fracture Defect

The glass fiber reinforced epoxy resin matrix composite shell was prepared by wet winding, the basic mechanical properties of the composite laminates were evaluated by tensile tests, double cantilever beams and three point end opening bending tests. And then the obtained strength and stiffness parameters were used in the finite element simulation. Meanwhile, a 3D progressive damage finite element model of composite shell containing fracture defects of different depths was established in Abaqus to predict the mechanical response of the shell under internal pressure. The results show that the tensile strength of the composite is （222.7 ± 18） MPa and the main elastic modulus is 39.39 GPa. The fracture toughness of typeⅠand type Ⅱ of interlayer strength are （4.67 ± 0.24）kJ/m² and （4.98 ± 0.26）kJ/m², respectively. As the internal pressure increases, Mises stress is increasing. The Mises stress is the largest when the fracture defect is in the deepest layer (the first layer close to the internal pressure, the depth is 18 mm). And when the internal pressure is 0.3 MPa, maximum Mises stress is up to 28.8 MPa, and the circumferential strain is less than the longitudinal strain.