论文部分内容阅读
为了研究复合材料吸湿过程中的Non-Fickian行为,建立基于应变的湿扩散方程,可以更准确地描述复合材料吸湿量随时间的变化关系。基于应变的湿扩散方程中考虑湿浓度与湿热应变间的相互耦合作用,假设应变也具有“扩散”行为,引入应变扩散系数与应变耦合项,并根据经典层压板理论计算层压板吸湿过程中产生的瞬时内应力状态。分析结果表明,基于应变的湿扩散方程所得到的吸湿量随时间变化的曲线与试验结果符合较好,层压板的湿浓度与湿热应变的相互耦合作用会影响吸湿量及湿热内应力的计算,在分析中不可忽略。受热和吸湿过程中产生的瞬态应力非均匀分布于层压板内,在复合材料结构设计时必须予以考虑。
In order to study the Non-Fickian behavior of composites during hygroscopic process, a strain-based wet-diffusion equation was established to describe the change of hygroscopicity of composites with time more accurately. Based on the interaction between wet concentration and wet-heat strain, the strain-based wet diffusion equation is also assumed to have “diffusion ” behavior. The coupling coefficient between strain diffusion coefficient and strain is introduced and the laminate moisture absorption process is calculated according to the classical laminate theory In the transient internal stress state. The results show that the curve of moisture absorption with time obtained by the strain-based wet diffusion equation is in good agreement with the experimental results. The mutual coupling between the wet strength of the laminate and the wet-heat strain will affect the calculation of the moisture absorption and the thermal stress. In the analysis can not be ignored. Transient stresses generated during heating and moisture absorption are non-uniformly distributed in the laminate and must be taken into account when designing the composite structure.