Figure 1. Schematic of the polymer network and shape-memory effect in a simple cycle based on combined mechanical loading and irradiation. In all figures, the filled circles  indicate chemical crosslinks in the original network, the open squares indicate unbonded chromophores, and lastly the filled squares indicate bonded chromophores. The thick blue line indicates the temporary shape, and the dashed line theoriginal reference body for this simple shape-memory cycle.

Figure 2. Verification for the radiative transfer problem on an unstructured mesh for (a) two-dimensions, and (b) three-dimensions. The top shows the computed finite element solution, the middle the analytical, and thebottom is the absolute value of the difference error.

Figure 3. Comparison of numerical solutions against analytical solution (given by the solid line) for a simple shape-memory cycle under uniaxial compression. (a) Uniaxial stretch versusnormalized stress response, (b) extent of bond reaction over time, (c) evolution of the normalized stress over time, and (d) evolution of the stretch over time.

Figure 4. Contours of the reaction extent on the deformed body at: (a) the end of the initial loading; after (b) 333 s, (c) 666 s, and (d) 1000 s of irradiation at wavelength of 300 nm during the crosslinking reacation; (e) the unloaded temporary shape; (f) after 400 s, g) 2000 s, (h) and 8000 s of irradiation at a wavelength of 200 nm during the cleavage reaction. In all cases, the thick black lines indicate the initial body, and note the change in scale foreach figure. We note that the values shown in the legend outside the range are an artifact of the interpolation for visualization only.

Figure 5. Contours of the reaction extent on the deformed body at: (a) the end of the initial loading; after (b) 333 s, (c) 666 s,and (d) 1000 s of irradiation at a  wavelength of 300 nm during the crosslinking reacation; (e) the unloaded temporary shape; (f) after 666 s, g) 1333 s, h) and 4000 s of irradiation at a wavelength of 200 nm during the cleavage reaction. In all cases, the thick black lines indicate the initial body and note the change in scale foreach figure. We note that the values shown in the legend outside the range are an artifact of the interpolation for visualization only.