弯扭载荷作用变刚度复合材料圆柱壳的屈曲优化

Buckling Optimization of Variable Stiffness Composite Cylindrical Shell Subjected to Bending and Torsion Loads

通过曲线纤维轨迹设计,变刚度复合材料圆柱壳将拥有比常刚度(直线纤维)圆柱壳更好的抗屈曲稳定性。为研究弯扭载荷作用下曲线纤维铺层形式和几何参数对变刚度复合材料圆柱壳屈曲性能的影响,建立了变刚度复合材料圆柱壳的参数化有限元模型,结合序列二次响应面方法和圆柱壳屈曲优化模型建立了复合材料圆柱壳曲线纤维轨迹优化的设计流程;以准各向同性铺层复合材料圆柱壳为比较基准,对弯扭载荷作用变刚度圆柱壳在不同铺层方式、不同几何参数下的屈曲性能进行了优化比较。数值结果表明:弯扭载荷作用下,变刚度圆柱壳的屈曲性能随弯矩载荷占比增加而提高,均好于准各向同性圆柱壳,但扭矩载荷占优时,优化常刚度圆柱壳的屈曲性能更具有优势。

The variable stiffness（ VS） composite cylindrical shell could be superior to traditional constant stiffness（ CS） counterpart in buckling resistance by fiber steering. The influence of layers and geometrical parameters on buckling property of composite cylindrical shell under bending and torsion loads is investigated by the parametric finite element model of a variable stiffness cylindrical shell.Combined with the sequence quadratic response surface method and the cylindrical shell optimization model for maximum buckling capacity,the design flow for the fiber trajectory optimization of the composite cylindrical shell was established. The buckling performances of VS cylindrical shell subjected to bending-torsion loading under different ply and geometric parameters were optimized and compared based on the quasi-isotropic ply-composite cylindrical shells. It is found that the buckling capacity of VS composite cylinder increases with the increase of the bending moment load,which is better than the quasi-isotropic cylindrical shell. However,when the torsional load is dominant,the buckling performance of the optimized CS cylindrical shell is more advantages.