基于数字图像相关方法的CFRP层合板高温压缩性能实验研究

Experimental study on compressive properties of CFRP laminates at high temperatures via digital image correlation

高温压缩性能是复合材料结构设计关键的力学参数,但是传统技术手段难以对其进行有效测量。通过搭建基于数字图像相关方法的高温实验系统,开展了复合材料的高温压缩实验,获得了130℃环境下CCF300/5228A碳纤维增强复合材料层合板0°和90°压缩性能、应力-应变曲线以及不同载荷情况下轴向应变分布及演化,并且与室温实验结果进行了对比。进一步通过扫描电镜进行了压缩试样的断口分析,结合实验结果,探讨了高温和铺层形式对压缩性能的影响。最后,通过实验验证了高温实验系统及相应实验方法的可行性和可靠性。结果表明:130℃环境下0°与90°压缩强度保持率分别为70.5%和62.6%,压缩模量保持率分别为88.0%和75.4%,说明由基体控制层合板的强度和模量对高温更敏感。

The high-temperature compressive properties are indispensable mechanical performance parameters for the structural design of composites, but it is difficult to be measured effectively by traditional techniques. In this study, the high temperature compressive experiment of carbon fiber reinforced plastics(CFRP) laminates was conducted in high-temperature experimental system based on digital image correlation(DIC) method. And the compressive properties, stress-strain curves and the evolution of axial full-field strain of CCF300/5228 A with 0° and 90° ply-ups at 130 ℃ were obtained. Moreover, they were compared with those obtained at room temperature. Furthermore, the fracture analysis of the compressed specimens was carried out through scanning electron microscopy(SEM), meanwhile the effects of high temperature and lay-up on the compressive properties were discussed combining with the experimental results. Finally, an experimental verification was carried out and the results obtained demonstrated the feasibility and reliability of the experimental system and relevant experimental methods. The results show that the retention rate of 0° and 90° compressive strength at 130 ℃ are 70.5% and 62.6%, respectively, while the retention rate of compressive modulus are 88.0% and 75.4%, respectively, indicating that the strength and modulus of the laminates which are controlled by the matrix are more sensitive to high temperature.