Zemer, Robert F.
Research Engineer, Douglas Aircraft Co., Inc., Santa Monica, Calif.
Pages: 9 Published: Jan 1960
This paper summarizes a portion of the work completed in conjunction with the environmental test program, sponsored by ASTM Committee C-19 on Structural Sandwich Constructions. This program, known as Project Alpha, consisted of 3-yr exposures of a variety of types of sandwich construction and core materials at two separate test sites. The first of these locations provided a marine atmosphere. This was at the Kure Beach, N.C., 80-ft site where a natural environment included exposure to a salt-water atmosphere, direct rays of the sun, wind-driven sand and spray, and several seasons of hurricanes. The second site was located on typical farm land at State College, Pa. There, the rural environment was the normal weather of the northeastern United States, including exposure to sun, wind, rain, snow, and ice. This paper includes results of tests following 1-, 2-, and 3-yr exposure of six types of test panels manufactured using Aeronautical Material Specification (AMS) 3722 paper-honeycomb. This honeycomb core utilized for this project was 125 lb kraft paper with 35 per cent impregnation of phenolic resin, the core was expanded 20 to 1 during manufacture to give a cell size of approximately 0.455 in. A variety of sandwich facing materials were evaluated. The manufacturing methods used to fabricate the various types of sandwich panels are also described.
Paper ID: STP46965S