High Strain Rate Properties of Angle Ply Composite Laminates,
IIT RESEARCH INST CHICAGO IL
Pagination or Media Count:
Angle ply graphiteepoxy and graphites-glassepoxy laminates were characterized in uniaxial tension at strain rates ranging from quasi-static -1 to over 5OOs . Laminate ring specimens of L5sub2s, -22.5sub2s, -30sub2s, -45SUB2S, -60sub2s, -67sub2s and -75SUB2S LAYUPS WERE LOADED UNDER INTERNAL PRESSURE. Results were presented in the form of stress strain curves to failure. Properties determined included moduli, Poissons ratios, strength, and ultimate strain. In all seven laminates for the two materials tested, the modulus and strength increase with strain rate. The effect of strain rate varies with layup, being lowest for the fiber dominated -15sub2s laminates and highest for the matrix dominated -75sub25 laminates. The highest increments over the static values are 10 to 25 for the -L5sub2s layup and 200 to 275 for the -75sub2s layup. Ultimate strains do not show any significant trends with strain rate. In almost all cases the ultimate strain values are within -20 of the mean value and in half of the cases the deviations from the mean are less than 10.
- Laminates and Composite Materials