含孔复合材料点阵夹层结构数值计算方法及其影响因素

针对含孔复合材料点阵夹层结构在面内压缩载荷作用下的失效模式及其影响因素问题,通过实验对含孔复合材料点阵夹层结构失效模式进行了研究;基于3D Hashin准则和Chang-Chang刚度退化准则建立了含孔复合材料点阵夹层结构有限元渐进损伤失效分析模型,并将计算结果与实验结果进行了对比;基于有限元分析方法探讨了开孔形状、开孔率以及开孔位置对其极限承载力的影响。结果表明:当点阵夹层结构面板厚度较大时,含孔复合材料点阵夹层结构的主要失效模式为面板圧溃;通过对比有限元计算结果和实验结果,极限承载力的最大误差约为12%,失效位置与实验结果一致;当点阵夹层结构的对称面与载荷方向平行且孔的中心在对称面上时,面内压缩强度与开孔位置无关,主要受到开孔形状和开孔率的影响;当点阵夹层结构对称面与载荷方向垂直且孔的中心在对称面上时,边距大于一个胞元,面内压缩强度基本不变,边距小于一个胞元,面内压缩强度下降。

Numerical method and influencing factors of composite pyramidal truss core sandwich structures with a hole

Failure modes of composite sandwich column with pyramidal truss core containing a hole were studied through experiments aimed to study the failure mode and influencing factors of composite lattice sandwich structure with a hole under compression loads.Finite element analysis progressive damage failure mode of composite lattice sandwich structure with a hole was established based on 3D Hashin criterion and Chang-Chang stiffness degradation criterion,and the calculated results were compared with experimental ones.Based on the finite element method,the impact of the opening shape,ratio and position on its ultimate loading capacity was discussed.The result shows that when the face-sheet of lattice sandwich structure containing a hole is thinker,the main failure mode is face crushing. By contrast the results of finite element calculation and experimental ones,the maximum error of the ultimate load-ing capacity is about 1 2%,and failure position is consistent with the experimental results.When the center of the hole is in the symmetry plane parallel to the direction of the load,the compressive strength of the lattice sandwich structure has nothing to do with the opening position,mainly influenced by the opening shape and ratio.When the center of hole is in the symmetry plane perpendicular to the direction of the load,if the margin is larger than one cell size,the compression strength of the lattice sandwich structure substantially does’t change,otherwise the compres-sion strength decreases.