CNG-2型气瓶的数值模拟方法对比

THE COMPARISON OF NUMERICAL SIMULATION METHOD OF CNG-2 CYLINDERS

针对数值模拟时CNG-2型气瓶常用的两种模型——轴对称模型和三维壳单元模型存在的争议,对两种模型进行了详细的对比,并讨论了纤维缠绕角度对其结构的影响,得到以下结论：由于CNG-2型气瓶纤维缠绕角接近90°,轴对称模型和三维壳单元模型的应力分布基本相同;壳单元理论上的缺陷导致三维壳单元模型纤维层的径向应力为0,是两种模型结果存在差别的主要原因;对纤维缠绕角接近90°的CNG-2型气瓶进行应力分析时,轴对称模型可以代替三维壳单元模型,且计算工作量较小;当纤维缠绕角不为90°时,两种模型间的误差随缠绕角变化,且当缠绕角在90°-70°之间时,误差在5%以内,在工程允许范围内仍可使用轴对称模型进行应力分析。相关结论可为CNG-2型气瓶数值分析工作提供有益的指导。

For the dispute between two usually used models（ i. e. axisymmetric model and three-dimensional shell element model） in numerical simulation of CNG-2 cylinders,the results between two models was compared in detailed,and the effect caused by filament winding angle was discussed. The conclusion is that： for CNG-2 cylinders,when winding angle of the fiber layer was close to 90°,the stress distributions of two models are basically the same; the theoretical defects of shell element was the primary reason for the radial stress in fiber layer closed to zero when three-dimensional shell element model was used; when winding angle is equal to 90°,three-dimensional shell element model could be replaced by axisymmetric model when the stress analysis of CNG-2 cylinders stress was made,which can reduce computational workload; when the filament winding angle is not equal to 90°,the error between two models changed with winding angle,but is less than 5% when the angle ranged from 90° to 70°,and axisymmetric model can also be used within the engineering permissible range. Those conclusions can provide beneficial guidance for hoop-wrapped composite cylinders numerical analysis.