Figure 1

Onset of sliding in the edge (EL) and uniform (UL) loading configurations. (a) and (b) Schematic views of the loading configurations and corresponding stress profiles. The stress profile at the interface (red shaded regions) is highly nonuniform for the EL and almost uniform for the UL. (c) Force traces corresponding to the EL (black curve) and UL (red dashed curve). (d) Ratio of static friction forces calculated for the EL and UL as a function of $K_{\mathrm{sur}}/K_{sl}$. The black line and red circles represent results of analytical calculations in Eq. (3) and simulations obtained for the case of a single detachment front initiated at the trailing edge and traversing the entire interface. Results of simulations performed for realistic values of parameters (blue triangles) show a sharp transition from a multiprecursor regime to a single detachment front that occurs at $K_{\mathrm{sur}}/K_{sl}\approx 5$. Parameter values used in model: $M=0.115$ kg, $V_0=3·{10}^{-4}$ m/s, $\tau =0.005$ s, $N_S=20$, $N=70$, ${\gamma }_0=\sqrt{K_{\mathrm{int}}/m}=3.6·{10}^5{\text{s}}^{-1}$, $f_s=2.14$ N, $\Delta f_s={10}^{-1}$ N, $k=\langle k_i\rangle =7.8·{10}^5$ N/m. In panel c $K_{sl}=3·{10}^6$ N/m and $K_d=1.5\times {10}^7$ N/m. For the above values of parameters $F_{\max }=3000$ N.Reuse & Permissions

Figure 2

Static friction and the evolution of surface stress profiles. Force traces (a) and surface stress entropy $S$ (b) vs time for three values of $K_{sl}$. There is a clear correlation between a variation of lateral force $F$ and entropy $S$. (c) and (d), 2D maps of surface stress evolution for $K_{sl}=K_0$ and $K_{sl}=25K_0$, where $K_0=3·{10}^6\mathrm{N}/\mathrm{m}$. Hotter (colder) colors indicate regions of higher (lower) stress. The bars to the right of the maps set up a correspondence between the colors and the values of the force in Newton.Reuse & Permissions

Figure 3

The effect of Poisson's expansion on static friction. (a) Tangential force profiles $F_p$ prior application of shear loading. (b) Mean value of $F_s$ as a function of the amplitude $A$ for the EL (black circles) and UL (black squares) configurations. The red curves show the corresponding mean values of the surface stress entropy $\langle S\rangle$.Reuse & Permissions

Figure 4

The effect of interfacial dissipation on static friction. (a) $\langle F_s\rangle$ as a function of the damping coefficient $\gamma$ for the EL and UL. The red curves represent the corresponding mean values of the surface stress entropy $\langle S\rangle$. Panels (b) and (c) present color maps for the number of attached contacts as functions of the block number and time. The bar to the right of the maps sets up a correspondence between the colors and the number of detached contacts.Reuse & Permissions

Figure 5

Onset of the first rupture front for the indicated values of $K_d$ and $\gamma$. Left panels show propagation of cracklike precursors, which is characterized by an instantaneous position of the precursor tip reported in terms of the number of detached blocks. Right panels present displacements of the $i$th block $x_i$ as a function of time for the indicated values of $i$. A contact between the block and the substrate is ruptured when $x_i$ exceeds the threshold value $x_{si}=f_{si}/k_i$ (dashed-dotted lines). In the simulations reported here ${\gamma }_0=\sqrt{K_{\mathrm{int}}/m}=59.5{\text{s}}^{-1}$, and other parameters as in Fig. 1 in the text.Reuse & Permissions