Figure 3.
Small indentation. The dependence of the dimensionless shell stiffness k1 ℓb2/B on the dimensionless pressure τ, which is defined in equation (3.5). The solid curve shows the theoretical prediction (3.6), which is approximated by the result of Reissner [13], k1∼8B/ℓb2, for τ ≪ 1 (dashed line) and by equation (3.7) for τ ≫ 1 (dotted curve). Open points show the results from simulations with shell thicknesses h = 2 mm (blue squares) and h = 5 mm (red circles). All other material properties are as in figure 2a. Solid points (green triangles) show experimental results obtained using a Pezzi ball with error bars given by repeated trials at different loading speeds. (Online version in colour).