Figure 5.

a,b. Collagen fibrils cycled in post-regime II, showing steady-state hysteresis both before (brown symbols) and after (blue symbols) a 60-min relaxation interval. c. Inelastic strain reaching steady-state after the first five cycles. d. Elastic modulus in regime I (E₁) and regime II (E₂). e. Energy dissipation per loading cycle reaching steady-state after the first five cycles before and after relaxation. For the data shown, the fibril diameter was 100 nm. Mean value of f. inelastic strain, g. elastic moduli E₁ and E₂, and h. hysteresis vs. cycle before and after relaxation for all (5) cyclic tests conducted in post-regime II. The inelastic strain was normalized with the steady-state value in the 10^th cycle, while the hysteresis was normalized with the value of the first cycle. Statistical data for inelastic strain and hysteresis are presented in normalized form because their absolute values depend on the applied λ_max (see later Figure 6a). The error bars correspond to one standard deviation.