VARI成型泡沫夹芯壁板结构界面性能
Interface properties of foam-core sandwich structures fabricated by VARI process
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摘要: 针对真空辅助成型工艺(VARI)制备的泡沫夹芯壁板面-芯界面粘接强度较低的问题, 提出铺放本体树脂胶膜和对芯材进行打孔两种解决方案。通过无损检测、三点弯曲力学性能测试、计算机模拟树脂充模流动以及微观界面结构观察, 探究两种方案的可行性及改善效果, 分析了胶膜的有无和厚度、打孔工艺参数对界面性能的影响。结果表明, 在不加入胶膜时界面强度最高, 胶膜厚度在0.5 mm时, 无损检测显示的界面缺陷最少, 胶膜厚度达到2 mm后界面质量下降; 合理设计芯材的打孔行、间距可以促进树脂充模流动, 形成质量好的连续界面, 同时还能提高结构刚度。Abstract: Two methods, i.e. laying resin bonding film at the face-core interface and using foams with well-arranged holes, were proposed aiming to improve the face-core interface properties of sandwich panels fabricated by vacuum assisted resin infusion(VARI) process. The possibility and benefits of these methods were investigated. Moreover, the influence of the existence of resin film and its thickness and density of holes in the foam core were investigated by non-destructive test, three-point bending test, computer simulation and interface microstructure observations. The analysis results indicate that sandwich structures without resin film achieve the highest face-core interface strength, while with 0.5 mm resin film show the fewest defects in non-destructive testing(NDT). When the film is as thick as 2 mm, the interface properties will deteriorate. Well-arranged holes in the foam core can promote infiltration process through the whole thickness of the sandwich construction, resulting in good interfacial and high stiffness.