航空复合材料加筋板湿热环境下吸湿性能

Moisture absorption performance of composite stiffened panels in hygrothermal environment

为探究复合材料加筋板湿热环境下的吸湿性能,开展了70℃、水浴环境下复合材料加筋板吸湿试验,分析其吸湿量变化规律,并通过数据拟合进行验证。针对Fick吸湿模型的局限性,提出了考虑侧边吸湿效应的修正两阶段吸湿模型;同时基于有限元方法建立了加筋板吸湿性能有限元分析模型,模拟吸湿过程中加筋板内水分的扩散及分布规律。结果表明:试验中3件试验件饱和吸湿量分别为0.702%、0.696%和0.687%,且吸湿过程可分为前期线性快速吸湿和后期吸湿速率放缓直至平衡两个阶段。利用试验数据验证了修正模型计算结果的准确性,通过与文献对比证明了该模型可提高预测精度。通过有限元模型发现试件表面迅速达到吸湿平衡,薄板区域比厚板区域更快达到吸湿平衡状态。

In order to investigate the moisture absorption performance of composite stiffened panels in hygrothermal environment,the moisture absorption experiment of composite stiffened panels under 70℃and water bath environment was carried out to analyze the law of moisture absorption,and verified by data fitting.In view of the limitations of the Fick moisture absorption model,a modified two-stage moisture absorption model considering the side moisture absorption effect was proposed.At the same time,based on the finite element method,the analysis model of the moisture absorption performance of the stiffened panels was established to simulate the diffusion and distribution of moisture in the moisture absorption process.The results showed that the saturated moisture absorption of the three experiment specimens was 0.702%,0.696%and 0.687%,respectively,and the moisture absorption process can be divided into two stages:linear rapid moisture absorption in the early stage and lower absorption rate until equilibrium in the later stage.The accuracy of the calculation results of the model was verified by using the experimental data,and comparison with the literature proved that the model can improve the prediction accuracy.Through the finite element model,the results exhibited that the surface of the specimen reached moisture absorption equilibrium rapidly,and the thin plate area reached moisture absorption equilibrium faster than the thick plate area.