Accession Number : AD0623051

Title :   STUDY OF RESIDUAL STRESSES IN THICK GLASSFILAMENT-REINFORCED LAMINATES.

Descriptive Note : Final rept. for 30 Jun 64-15 Oct 65,

Corporate Author : DOUGLAS AIRCRAFT CO INC SANTA MONICA CALIF ADVANCE STRUCTURES AND MECHANICAL DEPT

Personal Author(s) : Stone,F. E.

Report Date : 15 OCT 1965

Pagination or Media Count : 177

Abstract : A study was made to determine the presence, magnitude, causes, effects, and methods of controlling residual stresses in filament-reinforced plastic (FRP) structures for deep submergence application. Residual radial and hoop stresses are described for 18 cylinders of dispersed (4H:2L) construction and 46 all-hoop rings. Four methods of residual-stress analysis are reported and compared. Residual-stress trends are shown as a function of laminate thickness, radius, construction, winding tension, and mandrel temperature. The critical fabrication effects are identified, and the relative effects of most fabrication variables are compared. Residual-stress effects are examined with respect to interlaminar shear, compression, and buckling strength. Results indicate that residual axial and radial stresses are negligible for the thicknesses investigated and that the residual-stress effect on interlaminar shear strength, bending stiffness, and buckling strength is also negligible. Void content was found to affect laminate stiffness and have a pronounced effect on interlaminar shear strength--particularly on shear fatigue. (Author)

Descriptors :   (*LAMINATED PLASTICS, FILAMENT WOUND CONSTRUCTION), (*COMPOSITE MATERIALS, FILAMENT WOUND CONSTRUCTION), (*SUBMARINE HULLS, FILAMENT WOUND CONSTRUCTION), (*FILAMENT WOUND CONSTRUCTION, COMPOSITE MATERIALS), (*GLASS TEXTILES, REINFORCING MATERIALS), STRESSES, CYLINDRICAL BODIES, MATHEMATICAL ANALYSIS, STRUCTURES, RINGS, WINDING, BUBBLES, TENSILE PROPERTIES, THICKNESS, TEMPERATURE

Distribution Statement : APPROVED FOR PUBLIC RELEASE