封闭条件下胶接单搭接头固化过程的实验与数值模拟

Experimental and Finite Element Analysis on the Curing Process of Single-Lapped Adhesive Joint in a Closed Condition

汽车板胶粘件外部环境的封闭条件对胶接接头的固化情况影响很大。文中对封闭条件下单搭胶接接头的固化过程进行了实验研究,找出了钢板单搭胶接接头搭接区域温度以及胶粘剂固化度随固化时间的变化规律。为了预测封闭单搭接头固化过程中胶层的固化度变化规律,根据热传导以及固化动力学理论对其固化过程进行三维数值建模,利用实验对模型计算结果进行了验证,通过数值计算发现,固化过程开始时,接头升温速度较慢、且接头整体温度分布不均匀,搭接区域温度较低、两端温度较高,随着固化时间延长,接头升温速率加快,而接头总体温度分布越来越均匀。

The enclosure conditions have great influence on the curing of adhesive-bonded joints. Experiments were conducted to learn the curing of adhesive joint in a closed condition,the influence of curing time on the temperature of joint and curing degree of adhesive layer was obtained. In order to predict the curing degree of joint in a closed condition,3-D finite element model based on heat transferring model and cure kinetics were developed to model the curing of joint,simulation was validated by experiment results. The results indicate that the temperature distributions of the joints are not even at the beginning of the curing,temperature on the single-lap area is lower than the left and right side. With the curing time increase,temperature distribution becomes more uniform in the joint. With the increase of curing time,the degree of curing of joints increases slowly at first then increases greatly.