关键词: U-cor, 起圈织物, 泡沫夹芯, 低速冲击响应, 抗冲击性能, 复合材料

Abstract: According to the ASTM test standard D7136, the impact test of low impact impact on the wound fabric foam sandwich composite (U-cor) was carried out by drop hammer impact test. Four kinds of sandwich density, two kinds of sandwich thickness and three kinds of panel layers were prepared by polyurethane foaming process. The impact tests were carried out under the energy of 5 J, 10 J and 15 J, respectively. The experimental results show that under low energy impact, when the density of sandwich is pretty high, the contact force-time history curve is close to a quadratic curve symmetrical along the vertex. When the impact energy increases to a certain extent, the maximum contact load of loop starting fabric sandwich panel is higher than that of the same type of plain weave fabric sandwich panel. Due to the special forming process of the foam core sandwich composite with loop fabric, the increase of the core thickness will increase the local stiffness near the impact surface when the average density of the sandwich is the same, which will lead to a larger difference in impact response and an increase in impact resistance of sandwich panels with different thickness.

Key words: U-cor, loop fabric, foam core, low velocity impact response, impact resistance, composites