RTM玻璃纤维/E51环氧树脂复合材料孔隙含量对超声特征参数的影响

在0.1~0.35 MPa的树脂注射压力条件下，制备了孔隙含量不同的玻璃纤维连续毡/E51环氧树脂的树脂传递模塑（RTM）工艺试件，采用超声法、金相法和密度烧失法测量试件的孔隙含量。讨论了孔隙含量随树脂注射压力变化以及孔隙含量对RTM玻璃纤维/环氧树脂复合材料超声参数和力学性能的影响规律。结果表明，树脂注射压力的变化对孔隙含量产生明显影响，注射压力由0.1 MPa增加到0.35 MPa过程中，玻璃纤维连续毡/E51环氧树脂复合材料的孔隙含量从9.95%减小至3.73%。超声特征参数随孔隙含量的增加呈近于线性递增，尤其是超声非线性特征参数的变化更加明显，超声特征参数的变化可评价复合材料孔隙含量。

Effect of void content on ultrasonic characteristic parameters of RTM glass fiber/epoxy composites

The RTM process specimens of glass fiber continuous mat/E51 epoxy resin with different void content were prepared by applying different injection pressure (0.1-0.35 MPa). The void content of the specimen was measured by ultrasonic method, metallography and density measurement/resin burnout method. The relationship between void content and resin injection pressure was investigated. Effect of void content on ultrasonic parameters and mechanical property of RTM composites was discussed. The results show that, the change of resin injection pressure has a significant effect on the void content. The injection pressure increases from 0.1 MPa to 0.35 MPa, and the void content of glass fiber continuous mat/E51 epoxy resin composites decreases from 9.95% to 3.73%. Ultrasonic characteristic parameters are nearly linearly increased with the increasing of void content, and especially the change of ultrasonic nonlinear characteristic parameters are more obvious. The change of ultrasonic parameters can evaluate void content of composite materials.