湿热环境下K-cor夹层复合材料的力学性能

Mechanical properties of K-cor sandwich composite under hygrothermal environment

K-cor夹层结构是应用Z-pin技术增强的一种新型高性能夹层结构,本文研究了Z-pin不同植入密度对K-cor夹层结构试样吸湿特性的影响规律,在此基础上对不同Z-pin植入参数对试样湿热前后三点弯曲性能和压缩性能的影响规律进行了深入研究。研究结果表明:夹层结构中Z-pin的植入能提高试样的尺寸稳定性,且不会对其吸湿率造成明显影响;Z-pin植入密度的增加能明显提高湿热前后试样三点弯曲强度和压缩强度,且具有较高的强度保持率,Z-pin密度为12mm×12 mm的K-cor夹层结构湿热处理试样的三点弯曲强度比未湿热处理空白试样的要高11.1%,8 mm×8mm湿热处理K-cor试样的芯部压缩强度比未湿热处理空白夹层结构试样要高17.5%,体现出K-cor夹层结构优异的抗湿热性能;而Z-pin植入角度的减小能明显提高试样湿热处理前后的压缩强度,0°植入K-cor试样湿热处理后的芯部压缩强度与40°植入K-cor试样未湿热处理的基本相同,但植入角度对三点弯曲强度影响较小。

K-cor sandwich is a new kind of foam sandwich reinforced by Z-pin techniques. The absorption curves of different samples by changing the implanted density of Z-pin are investigated, and the effect of the hydrothermal condition on the three point bending and compressive properties of the samples with changing parameters of Z-pin are also determined. The results indicate that Z-pin improves the dimensional stability of the samples by changing the implanted density in sandwich structure, but it does not affect the moisture absorption rate. The sample which increases the implanted density of Z-pin can significant- ly improve the three point bending strength and compressive strength under dry and wet conditions, and the samples have a higher strength retention rate. The three point bending strength of K-cot with Z-pin density of 12 mmx 12 mm in wet condition is improved by 11.1%, and the compressive strength of K-cor with Z-pin density of 8 mm x 8 mm in wet condition is improved by 17.5 % compared with blank sandwich structure in dry condition. It shows that K-cor sandwich structure has excellent wet and heat resistance. The samples which reduce implantation angle of Z-pin can significantly increase the compres- sive strength under dry and wet conditions. The compressive strength of K-cor sample with Z-pin of 0° in wet condition is the same as Z-pin of 40° in dry condition. But this factor has less influence on three point bending strength,