纤维缠绕复合材料壳体刚度衰减模型数值模拟

应用微分几何理论,推导出纤维缠绕复合材料壳体的非测地线缠绕轨迹、包角方程及绕丝头运动方程,得到缠绕过程的动态仿真模拟数据。将封头处变化的缠绕角、厚度等实际工艺参数直接用于壳体结构的理论分析。采用叠层的增量本构关系,模拟层合板壳结构的损伤过程,建立了损伤后刚度衰减模型及刚度退化准则,并通过实验确定了刚度衰减系数。应用此模型对纤维缠绕复合材料压力容器进行了数值分析。结果表明:纤维缠绕复合材料压力容器封头处损伤会导致其弯曲刚度降低,这是影响轴向变形的重要因素。 

NUMERICAL SIMULATION OF STIFFNESS DEGRADATION MODEL FOR FIBER-WINDING COMPOSITE PRESSURE VESSELS

Non-geodesic trajectory mandrel rotation and motion equations of the eye for fiber reinforced composite pressure vessels were derived by the theory of differential geometry. Practical winding parameters such as winding angle and thickness can be applied directly to stress analysis. The incremental constitutive model of laminate and piecewise linear methods were used to simulate the process of laminate damage. A new stiffness degradation model and test methods were introduced. An experimental method which determined the factor of stiffness degradation was also demonstrated . Numerical analysis for filament wound pressure vessels was finished by using this model. The results show that flexural stiffness degradation is the main factor which affects the axial displacement after the initial damage occurs.