Impact Strength of Angle Ply Fiber Reinforced Materials.

摘要

Tensile strength of angle ply balanced laminates made of glass fibers and epoxy matrix has been investigated under impact loading. An instrumented drop weight apparatus was used to apply the load and measure stress and strain during the impact process. Theoretical stress-strain curves are compared to experimental ones. Good agreement is shown to exist for fiber orientation above plus or minus 45 degrees while for lower fiber orientation the agreement is only for part of the loading process. It is shown that different failure criteria have to be used for different ranges of fiber orientation. Above plus or minus 40 degrees the experimental failure stresses agree well with theoretical predictions while below this angle the experimental values are supplemented by a qualitative discussion only. Failure stresses in the dynamic case are found to be considerably higher than the corresponding static values for the complete range of fiber orientation. The failure strains and initial effective modulus are the same for static and for impact loadings.