The axis in the plane of a laminate perpendicular to the x-axis.
A continuous, ordered assembly of essentially parallel, collimated filaments, usually with a twist.
The first stress in a material, less than the maximum rate attainable stress, at which the strain increases at a higher rate than the stress. The point at which permanent deformation of a stressed specimen begins to take place. (Also see stress and strain.)
Ratio of normal stress to the corresponding strain for tensile or compressive stresses less than a material's proportional limit.