Horizontal shear testing of woven fiberglass/epoxy composites /

Abstract

In this program horizontal (apparent) shear data from a number of quality control efforts were compiled and augmented by additional tests. The data were used to show the effects of test parameters, cure conditions, and material age on the apparent shear. Failure modes were recorded. Findings include: (1) Based on the horizontal shear test, CE 9000 (Ferro Corp.) should not be postcured above 370 F, and the desirability and effects of a postcure between 350F and 370F should be explored before committing to this postcure condition. (2) Autoclave cure of CE 9000 will increase its resin dominated shear properties 50% or more, compared to vacuum-bag, oven-cured parts. An appreciable drop in apparent shear using the short beam method occurs as S/t6 is increased. Data should be normalized to a consistent S/t for comparison. (3) The predominant damage pattern for woven glass coupons is related to S/t and the degree of cure. (4) Certain woven glass composites require an S/t well below 5 to achieve shear failure. (5) Short beam specimens of the type investigated should be fabricated with peel plies or porous release cloth on both sides.Research supported by the United States Air Force Wright Aeronautical Laboratories."Final Report for Period January 1979 - April 1982.""October 1983."Includes bibliographical references (page 42).In this program horizontal (apparent) shear data from a number of quality control efforts were compiled and augmented by additional tests. The data were used to show the effects of test parameters, cure conditions, and material age on the apparent shear. Failure modes were recorded. Findings include: (1) Based on the horizontal shear test, CE 9000 (Ferro Corp.) should not be postcured above 370 F, and the desirability and effects of a postcure between 350F and 370F should be explored before committing to this postcure condition. (2) Autoclave cure of CE 9000 will increase its resin dominated shear properties 50% or more, compared to vacuum-bag, oven-cured parts. An appreciable drop in apparent shear using the short beam method occurs as S/t6 is increased. Data should be normalized to a consistent S/t for comparison. (3) The predominant damage pattern for woven glass coupons is related to S/t and the degree of cure. (4) Certain woven glass composites require an S/t well below 5 to achieve shear failure. (5) Short beam specimens of the type investigated should be fabricated with peel plies or porous release cloth on both sides.Mode of access: Internet