含有断裂缺陷的复合材料壳体的力学行为

Mechanical Behavior Analysis of Composite Shell with Fracture Defect

利用湿法缠绕制备了玻璃纤维增强环氧树脂基复合材料壳体,通过拉伸、双悬臂梁和三点端部开口弯曲试验对该复合材料层合板进行基本力学性能评估,得到强度和刚度参数并用于有限元模拟中。同时,在Abaqus中建立了含有不同深度断裂缺陷复合材料壳体的三维渐进损伤有限元模型,预测内压作用下壳体的力学响应。试验和模拟结果表明:复合材料主向拉伸强度为(222.7±18)MPa,弹性模量为39.39 GPa,Ⅰ型和Ⅱ型断裂韧性层间强度分别为(4.67±0.24)和(4.98±0.26)kJ/m^(2)。随着内压增大,Mises应力也不断增大;当断裂缺陷在最深层(接近内压的第一层,深度为18 mm)时,Mises应力最大;当内压为0.3 MPa时,Mises应力高达28.8 MPa,且周向应变小于纵向应变。

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 typeⅡof interlayer strength are(4.67±0.24)kJ/m^(2) and(4.98±0.26)kJ/m^(2),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.