齿板-玻璃纤维混合夹层结构弯曲性能试验

Experimental study on flexural performance of tooth-plate-glass-fiber hybrid sandwich beams

提出了一种齿板-玻璃纤维混合面板和泡沫芯材组成的新型混合夹层结构,齿板通过齿钉与泡沫芯材相连。该结构采用真空导入成型工艺制备,通过三点弯曲试验研究该结构在不同跨度以及不同芯材密度情况下的破坏模式和弯曲性能,并与普通泡沫夹层结构进行对比分析,同时探究了齿板对该结构界面性能的影响。结果表明:在泡沫芯材密度为35kg/m^3、80kg/m^3和150kg/m^3情况下,齿板-玻璃纤维混合泡沫夹层梁弯曲承载能力与普通泡沫夹层梁相比分别提高了168%、211%和258%,其界面剪切强度依次为0.09 MPa、0.21 MPa和0.45 MPa;随着芯材密度和跨度的变化,该结构主要产生芯材剪切和芯材凹陷两种破坏形态,齿板的嵌入有效抑制界面的剪切失效。另外,利用理论公式估算了试件受弯极限承载能力,理论值与实测值吻合较好。

The hybrid sandwich structure consistes of tooth-plate-glass-fiber facesheets and a foam core.Tooth plate was connected with foam core through tooth nails.Tooth-plate-glass-fiber hybrid sandwich beams were made by vacuum assisted resin transfer molding.Compared with the normal sandwich structures,the failure mode and flexural performance with different spans and core densities were investigated by three-point bending tests.Meanwhile,the influence of the tooth plate on the interfacial property was also studied.The test results show that in the case of foam core density of 35 kg/m^3、80 kg/m^3 and 150 kg/m^3,the ultimate bending strength increases by 168%,211% and 258%,respectively,compared with the normal sandwich beams and the interfacial shear strength are0.09 MPa、0.21 MPa and 0.45 MPa in turn.With the change of core density and span,the structures mainly occur two kinds of failure modes,which are core shear and core indentation.The tooth plate suppresses shear failure effectively.In addition,the analytical model used to predict the ultimate bearing capacity of specimen was proposed.The calculated results are in good accordance with the experimented results.