玻璃钢-聚氨酯泡沫夹层板弯曲失效研究

采用真空灌注方法研制了玻璃纤维-聚氨酯泡沫夹层板，通过理论推导、数值仿真及试验验证对该夹层板的弯曲失效特性进行了研究，得到了实际失效载荷以及两种失效模式。研究表明，玻璃纤维-聚氨酯泡沫夹层板的载荷变形曲线中会出现2处拐点：第一拐点对应第一失效模式，其表征为表层玻璃纤维被拉伸断裂；第二拐点对应第二失效模式，其表征为芯体泡沫被剪切开裂。

The bending failure of fiberglass-polyurethane foam sandwich panel

In order to study the bending failure mechanism of composite sandwich panels, the fiberglass- polyurethane foam sandwich panel is designed and manufactured by vacuum infusion. A theoretical model for its failure is built and the bending test is carried out, as well as the numerical simulation. The failure load is obtained, and two failure modes are revealed during the bending process. An explanation of two inflexion points observed in the load-deflection curve of the glass fiber-polyurethane foam sandwich panel is made. It is concluded that the first inflexion point, corresponding to the first failure mode, is owing to the tensile splitting of the surface glass fiber, and the second one, corresponding to the second failure mode, is due to the shear force splitting of the middle foam.