不同温度下树脂基复合材料层合板力学性能试验

通过试验的方法研究了双马来酰亚胺树脂浇注体及碳纤维增强树脂基复合材料单向层合板在不同温度下的静态力学性能,并讨论了温度对材料力学行为的影响,最后对材料断口形貌进行了分析.试验结果表明:纯树脂浇注体拉伸、压缩性能受温度影响比较明显,且拉、压性能不同.对于拉伸性能,相对室温均值(20℃),160℃环境下模量均值及强度均值降幅分别为31.73%,44.71%,200℃时又分别下降了21.15%,20.37%;对于压缩性能,相对室温均值,160℃下模量及强度均值分别下降了26.67%,44.40%,而200℃时继续下降了6.66%,12.40%.层合板的纵向拉伸性能受温度影响较小,在200℃内,纵向模量与强度最大变幅分别为2.82%和2.53%,且材料断口从室温下的"毛刷"状变为了沿轴向劈断.材料的横向及面内剪切性能受温度影响较大,且应力-应变曲线存在明显非线性,但横向试件断口平整、面内剪切试件无明显紧缩现象,即均表现为脆性断裂特征.另外,相对室温均值,在160℃时,横向及面内切变模量分别下降约32.96%,41.25%,强度分别下降约15.83%,30.96%;在200℃时,横向及面内剪切性能继续下降,模量降幅为16.83%,22.52%,强度降幅12.24%,11.01%. 

Experiment on mechanical properties of resin matrix composites laminates under various temperatures

The mechanical properties of resin casting body and carbon fiber reinforced resin composite laminate were investigated under various temperatures experimentally. Influence of temperature on the stress-strain curve was discussed and then fracture surface analysis was also conducted. The experiment results showed that the tensile and compression properties of the resin casting body were obviously affected by temperature, and both of the properties were unequal. The average tensile modulus and strength fell by 31.73% and 44.71% compared with the value at room temperature (RT 20℃), and then dropped by 21.15% and 20.37%, respectively if continuing to heat up to 200℃. The average compressive modulus and strength at 160℃ decreased by 26.67% and 44.40% in comparison with those at RT, and the relative values continued to decline by 6.66% and 12.40%. For the composites, the longitudinal tensile property was hardly affected by temperature. The maximum amplitudes in the average stiffness and strength were only 2.82% and 2.53%. The longitudinal fractured surface morphology illustrated a "brushy" shape at RT, while a split configuration was observed at elevated temperature. The mechanical properties of transverse and in-plane shear were significantly affected by temperature and the stress-strain curve showed an obvious nonlinearity, however, a neat fractured surface subjecting to transverse loading and shear fractured surface had no significant necking appearance, which indicated brittle-natured fracture. The modulus of transverse and in-plane shear was reduced by 32.96%, 41.25% and the related strength declined by 15.83%, 30.96% at 160℃ compared with those at RT. When the temperature reached 200℃, the modulus continued to decline by 16.83%, 22.52%, and the corresponding strength dropped by 12.24% and 11.01%, respectively.