Modelling Cyclic Moisture Uptake in an Epoxy Adhesive
Modelling Cyclic Moisture Uptake in an Epoxy Adhesive
复制标题
DOI：
10.1080/00218460902997224
复制
发表时间：
2009-09
期刊：
影响因子：
--
通讯作者：
A. Mubashar;I. Ashcroft;G. Critchlow;A. Crocombe
中科院分区：
文献类型：
--
作者：
A. Mubashar;I. Ashcroft;G. Critchlow;A. Crocombe
本文提出了一种预测环氧树脂胶粘剂在循环吸湿-脱湿条件下的水分浓度的方法。通过循环湿度条件下的重量实验确定了该粘合剂的扩散特性，并确定了扩散系数和饱和质量吸收对湿度历史的依赖性。在吸收循环期间观察到非菲克水分吸收，而水分解吸保持菲克。扩散系数和饱和含水率随吸附-解吸循环而变化。提出了一种基于有限元法的循环含水率预测方法。新的建模方法和类似的方法，忽略了水分的历史依赖之间的比较。可以看出，浓度预测的基础上，非历史依赖的扩散特性，导致过度预测的水分浓度在粘接接头的循环调节。所提出的方法作为第一步，在制定一个通用的方法来预测水分依赖的降解和失败的粘合剂。
This paper presents a methodology for predicting moisture concentration in an epoxy adhesive under cyclic moisture absorption-desorption conditions. The diffusion characteristics of the adhesive were determined by gravimetric experiments under cyclic moisture conditions and the dependence of diffusion coefficient and saturated mass uptake on moisture history was determined. Non-Fickian moisture absorption was observed during absorption cycles while moisture desorption remained Fickian. The diffusion coefficient and saturated moisture content showed variation with absorption-desorption cycling. A finite element-based methodology incorporating moisture history was developed to predict the cyclic moisture concentration. A comparison is made between the new modelling methodology and a similar method that neglects the moisture history dependence. It was seen that the concentration predictions based on non-history dependent diffusion characteristics resulted in over-prediction of the moisture concentration in cyclic conditioning of adhesive joints. The proposed method serves as the first step in the formulation of a general methodology to predict the moisture dependent degradation and failure in adhesives.