含泡沫铝芯的复合板弯曲疲劳行为的研究

应用表面位移原位分析技术对由泡沫金属铝芯和金属面板组成的三层复合板在循环弯曲载荷条件下的损伤行为进行了观察和研究。循环弯曲载荷条件下复合板失效的基本方式是表面凹陷（Indentation，ID）和泡沫铝内芯切断（Coreshear，CS）。凹陷型失效是与加载压头接触的复合板表面局部压缩密切相关，该处沿垂直方向的压缩应变最大。内芯切断型失效是泡沫铝内芯中切应变最大的区域发生的剪切破坏。在疲劳应力比R=0时，复合板凹陷型失效的疲劳极限高于内芯切断型失效的疲劳极限。

Study on Fatigue Behavior of Sandwich Beams Consisted of Aluminum Foam Core under Bending Condition

This paper dealt with the mechanical behavior of sandwich beams composed of aluminum foam core and metallic face sheets under cyclic bending by in-situ Surface Displacement Analysis Software.For a certain sandwich,the basic operative failure mode is indentation(ID) and core shear(CS),which depends on the geometry of the sandwich beam.SDA results show that the ID is localized compression on the beam adjacent to inner rollers,where the strain is the maximum.As for the CS case,failure happens on the core between the inner and outer rollers where corresponds to the site of the maximum shear strain.At fatigue ratio R= 0,the fatigue limit of sandwich beams failing by the ID is higher than that of beams failing by the CS.