The first example we consider involves a bulky, highly deformable neo-Hookean rod. The rod is initially vertical and anchored at its top end. It is placed in a horizontal fluid flow, which causes it to deform significantly. The domain covers −2 ≤ x ≤ 2 and −2 ≤ y ≤ 2 using a square grid of size 240 × 240. The bar initially covers the rectangle −1.4 < x < 0.6 and and has semi-circular end caps. The anchored region is a circle with center (x, y) = (−1, 1.1) and radius ra. During the simulation, the reference map in the anchored region is enforced to be constant and the velocity is enforced to be zero. We have simulated two different anchor sizes ra = 0.25 (Fig. 3) and ra = 0.15 (Fig. 4). The fluid inflow and outflow is controlled by applying a constant horizontal velocity of (u, v) = (0.24, 0) on the left and right sides of the domain window. Perfect slip boundary conditions are used on the top and bottom sides, where v = 0, and u and ρf are free. In each simulation, the fluid flow deforms the rod inducing large local stretches in the solid, with stretch ratios exceeding two in parts of the bar. In the case of the smaller anchor, the bar is less able to resist the incoming fluid flow and swivels out of the way to a greater extent as expected. The simulations each reach a steady state by t ≈ 20 where the rod remains in a static, bent configuration with steady fluid flow surrounding it. On an Apple MacBook Pro (Mid 2014) system with a quad-core 2.8 GHz Intel i7 processor, the simulation using ra = 0.25 takes 997 s using 216,090 time steps using a single thread. If two, three, or four threads are used, the simulation takes 773 s, 705 s, and 635 s, respectively. Because this simulation only uses a small grid, the speedup from multithreading is only modest, since the overhead from creating threads is comparable the computational work done each time step. However, for some of the larger simulation grids considered later, multithreading becomes significantly more advantageous.