横隔板增强型泡沫夹芯复合材料梁抗剪性能试验研究

EXPERIMENTAL STUDY ON SHEAR BEHAVIOR OF REINFORCED FOAM CORE COMPOSITE SANDWICH STRUCTURES

复合材料泡沫夹芯结构易发生芯材剪切破坏,需对泡沫芯材进行增强。本文对比分析了不同增强泡沫夹芯结构的增强原理、芯材对界面性能和抗剪能力的贡献以及各自的局限;采用真空导入工艺制作了横隔板增强泡沫夹芯梁,并对其进行了剪跨比为3的三点弯试验,研究了横隔板及其间距对泡沫夹芯结构抗剪性能的影响。试验结果表明,横隔板的存在能有效提高构件的延性,且横隔板间距越小,延性越好,改善了泡沫夹芯结构脆性破坏的特性;但横隔板增强对夹芯梁强度和刚度的影响不大,该结果与垂直缝纫增强泡沫夹芯结构的试验结果类似。横隔板增强泡沫夹芯结构具有良好的设计性,其制作过程比较简单,可改变横隔板角度或采用双向隔板增强,从而在保持延性的优势下,提高其强度和刚度。

Reinforcement is necessary for the foam core composite sandwich structure because of the poor shear performance of the foam core. This paper presented several kinds of reinforced composite structures including their difference in design principles,their contributions to the interfacial property and shear behavior as well as their limitations. What＇s more,three point bending tests were conducted on the diaphragm reinforced foam core sandwich beams made through vacuum infusion process,in order to study the impact of the reinforced measure and the diaphragm span on the shear behavior. The experimental results showed that the existence of diaphragms may enhance beams＇ ductility,and the shorter the diaphragm span,the more enhancement in ductility,hence,the brittleness of foam core sandwich structure were greatly improved. However,there was little increase in strength and rigidity,which is similar to the experimental result of 90° stitch addition in sandwich structure. The diaphragm reinforced structure is simple made and well designed,and the change from diaphragm to inclined or biaxial diaphragm reinforced foam core composite structure may not only enhance its strength and rigidity,but also remain its advantage in ductility.