Figure 4.

The results of cyclic stress–strain tests on A. subfuscus glue. (a) A single sample of slug glue stretched to a strain of 2.8, then returned to its resting length. Arrows indicate loading and unloading. (b) A single sample of glue stretched through progressively larger strains, with a return to the original length after each extension. In this trial, the sample was stretched through four cycles to a peak strain of 3.6. (c) The effect of strain history on the total energy dissipated. The group of points on the left shows the total energy dissipated in samples taken through three progressively larger strain cycles (similar to part b). The group of points on the right shows the energy dissipated in paired samples taken to the same ultimate strain in a single cycle (similar to part a). Dashed lines link the results from pairs cut from the same sample. Samples were extended to strains of 0.9, 1.8 then 2.7 or directly to 2.7 with no previous extensions. N = 6. (Online version in colour.)