Abstract
The present work is an experimental study using an X-ray technique to measure directly the internal distribution of interlaminar-shear deformations which occur during uniaxial extension of two-ply, cord-rubber, angle-ply laminates—both balanced and unbalanced. Significant interlaminar-shear strains were developed between the two generally orthotropic layers of one-inch-wide specimens, which decreased almost linearly from a maximum at the edges to zero at the center line. These measurements, and those as a function of cord angle, were in good agreement with predictions obtained from various theories of laminated shear-flexible composites.
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Abbreviations
- A :
-
cross-sectional area of cord, in.2 (mm2)
- E f :
-
Young's modulus of cord, psi (MPa)
- E m :
-
Young's modulus of interply rubber, psi (MPa)
- G :
-
shear modulus of interply rubber, psi (MPa)
- \(\bar Q_{ij} \) :
-
transformed reduced-stiffness matrix, psi (MPa)
- S 11,S 12,S 22,S 66 :
-
principal compliances, psi−1 [(MPa)−1]
- \(\bar S_{16} \) :
-
shear-coupling compliance, psi−1 [(MPa)−1]
- b :
-
half-width of specimen, in. (mm)
- ℓ:
-
half-length of specimen, in. (mm)
- n :
-
number of cords/in. (perpendicular to cords)
- t :
-
thickness of interply rubber, in. (mm)
- t 0 :
-
thickness of composite layer, in. (mm)
- u, v, w :
-
displacements in x, y and z directions, respectively, in. (mm)
- γ:
-
shear strain
- ε:
-
normal strain
- θ:
-
angle between cord and loading direction of specimen, deg (rad)
- ν:
-
Poisson's ratio
- σ:
-
tensile stress, psi (MPa)
- ϕ:
-
included angle between cords in adjacent plies, deg (rad)
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Lou, A.Y.C., Walter, J.D. Interlaminar-shear-strain measurements in cord-rubber composites. Experimental Mechanics 18, 457–463 (1978). https://doi.org/10.1007/BF02324281
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DOI: https://doi.org/10.1007/BF02324281