图  1  倾斜胞壁Nomex蜂窝芯几何构型示意图

Figure  1.  Schematic representation of the inclined Nomex honeycomb

L—Length of the honeycomb; W—Width of the honeycomb; H—Hight of the honeycomb; F—Out-of-plane load; F_N—Normal load; F_S—Shear load; ϕ—Loading angle; h—Vertical cell wall length; l—Inclined cell wall length; ω—Inclined angle

图  2  蜂窝芯压剪复合试验装置

Figure  2.  Test set-up of a honeycomb core under combined shear-compression loading

CCD—Charge coupled device

图  3  倾斜胞壁Nomex蜂窝芯压剪有限元模型及边界条件

Figure  3.  Combined shear-compression finite element model and boundary condition of the inclined Nomex honeycomb

图  4  胞壁倾角ω=0°蜂窝芯实验与数值模拟应力-位移曲线对比

Figure  4.  Comparison of experimental and numerical stress-displacement curves for honeycomb with ω=0°

图  5  胞壁倾角ω=0°蜂窝芯实验与数值模拟初始峰值应力σ_p 及平原阶段强度σ_r对比

Figure  5.  Comparison of initial peak stress σ_p and plateau stage strength σ_r between experiment and numerical simulation for honeycomb with ω=0°

图  6  胞壁倾角ω=0°蜂窝芯实验与数值模拟胞壁变形对比

Figure  6.  Comparison of the deformation modes between the experiment and simulation for honeycomb with ω=0°

图  7  蜂窝的变形模式示意图

Figure  7.  Schematic of the deformation modes for honeycomb

图  8  不同胞壁倾斜角蜂窝芯结构在加载角$\phi $=15°下的应力-位移曲线

Figure  8.  Stress-displacement curves of inclined honeycomb at different inclined angle under the loading angle $\phi $=15°

图  9  加载角度及蜂窝倾角对蜂窝芯初始峰值力及平原阶段强度影响

Figure  9.  Effect of loading angle and inclined angle on the initial peak stress and plateau stage strength for honeycomb

图  10  加载角度及蜂窝倾角对蜂窝芯变形的影响(蜂窝芯位移为0.2 mm)

Figure  10.  Effect of loading angle and inclined angle on the deformation of honeycomb (Displacement of honeycomb is 0.2 mm)

图  11  L方向剪切应力作用下蜂窝壁对应的剪切力流

Figure  11.  Shear force flow in honeycomb cell when loaded in the L direction

τ₃₂—Shear stress; Q_a—Vertical cell wall shear flow; Q_b, Q_c—Inclined cell wall shear flow

图  12  不同胞壁倾斜蜂窝芯截面变化

Figure  12.  Cross sections of inclined honeycomb at different inclined angles

θ—Angle between inclined cell wall and horizontal

图  13  蜂窝胞壁倾角ω对芯格斜边尺寸l_i及夹角θ_i影响

Figure  13.  Effect of inclined angle ω on the cell wall length l_i and angle θ_i

图  14  倾斜胞壁蜂窝芯等效处理

Figure  14.  Equivalent of inclined cell wall honeycomb

图  15  胞壁倾角对倾斜胞壁蜂窝芯坍塌应力与垂直胞壁蜂窝芯坍塌应力比值的影响

Figure  15.  Effect of inclined angle on the ratio about the collapse stress of inclined cell wall honeycomb to the vertical cell wall honeycomb

$ \sigma _3^{ * * } $, $ \tau _{32}^{ * * } $—Collapse compression stress and shear stress of inclined cell wall honeycomb; $ \sigma _3^ * $, $ \tau _{32}^ * $—Collapse compression stress and shear stress of the vertical cell wall honeycomb