Identification and Validation of Analytical Chemistry Methods for Detecting Composite Surface Contamination and Moisture - Solid-State Electrochemical Sensor Study

摘要

Continuous improvement of the strength and durability of bonded structures is the key to the overall acceptance of the processing and fabrication technologies in aerospace industry, especially in applications of the technologies in manufacturing primary aircraft structures (1). The design principle for any adhesive-bonded joints or adhesive bonds requires that the cured adhesive is always stronger than the strength of the adherend (1). Surface pretreatment or preparation has been implemented in aerospace industry for many years as a process to ensure strong adhesive bonds. Many of the pretreatment procedures result in adhesive bonds that have high initial bond strength but do not always demonstrate expected durability (2,3). Service experiences with adhesive-bonded joints have been displayed variable strength and durability. Some provide extended service lives while others fail before the expected service lives. For example, adhesive bond failures were cited as the major cause for 53% of structural defects in the Royal Australian Air Force (1). Analyses of the bond failures have revealed that many of the adhesive-bonded joints failed at the interface between adhesive and adherend (adhesion failure mode) (4-7). Such a wide variation in bond durability (2,3,8-11) strongly suggests deficiencies in the quality control of the surface pre-treatment and bond fabrication processes and lack of an in-field definitive surface inspection method.