在制作固体火箭发动机绝热层人工脱粘缺陷的试件时, 经常采用嵌入聚四氟乙烯插片的方法来模拟脱粘缺陷。多数情况下, 插片很难取出。当插片与两侧材料不完全粘接时就会出现空气隙, 且试件的上表面会有一定程度的凸起。首先证明了某试件中的缺陷是插片和空气隙组成的混合缺陷, 然后进一步针对缺陷的组成、位置和凸起的有无建立了多种仿真模型并进行了仿真计算, 通过对仿真结果进行分析比较, 得出了一种计算精度较高、且比较简单的建模方法。

Polytetrafluoroethylene(PTFE) inserts are usually used as artificial disbond defects when making reference samples containing disbonds in the insulator of solid rocket motors. It is hard to take out the inserts in most cases. There will be air gaps once the poor bonding between the insert and the host material appears, in addition, the upper surface of the sample will bulge. In this paper, first, it is proven that the PTFE insert leads to a hybrid defect which consists of the insert and air gaps; then a variety of models are established for the different composition, position and bulge of the defect, and the corresponding numerical simulation is conducted; at last, a precise and simple modeling method is presented by comparing and analyzing the simulation results of these models.