Adhesive Bond Failures in Aircraft Honeycomb Sandwich Composites

摘要

A number of approaches were initiated to improve bond strength and durability of honeycomb core-sandwich structures, some of which are described in the report. The overall objective was to determine why and how these composites fail and then determine what can be done to eliminate or reduce these failures. Failure, in part, appears to be caused by an undercutting type of corrosion which destroys the bond. The adhesives themselves appear also to be partially to blame. Although their initial strength is probably sufficient, their durability to environmental conditions is poor. The deficiencies in the adhesive are inadequate moisture resistance, high void content, and brittleness. To correct these problems, corrosion-inhibitive primers and treatments are being studied, new water-resistant resins are being synthesized, and bonding procedures are being studied. (Author)