Figure 4.
(a) Dependence of the critical compressive stretch λcr on the obliquity angle θ, for different values of β in the shear-box compression test. As β varies from β=−1 (neo-Hookean material) to β=1 (extreme-Mooney material) (β= −1.0,−0.6,−0.3,0,0.3,0.6,0.8,1.0, see arrow), the maximum of the plot shifts from θ=0° (principal wrinkles appearing at 53% strain) to θ≃33° (oblique wrinkles, appearing at an earlier strain of 46%). (b) Flowchart for the corresponding numerical procedure. (Online version in colour.)