Non-affine dissipation in polymer fracture

Liu，Yazhuo; Feng，Xianke; Hong，Wei

2023-03-01

10.1016/j.eml.2023.101955

Extreme Mechanics Letters   Impact Factor & Quartile

2352-4316

Viscoelasticity is a universal property in most soft solids. Specifically, for the fracture of polymeric materials, viscoelasticity has often been regarded as a major mechanism of toughening, and the excess fracture energy beyond the intrinsic value correlated to the stress–strain hysteresis, which is commonly used to characterize viscoelasticity in the framework of continuum mechanics. Through systematically planned experiments, the current study shows that a noticeable package of energy dissipation exists besides that associated with the hysteretic deformation. This package of energy is attributed to the highly non-affine deformation near the crack tip — the rearrangement and mutual sliding of the neighboring chains caused by the rupture of a polymer chain, which are insignificant in samples under homogeneous deformation. Various means of inter-chain-friction reduction, e.g., by applying lateral stretches, diluting the chains with solvent, or subject the material to dynamic or static fatigue, can mitigate the effect of non-affine dissipation, and bring the fracture energy down to the intrinsic threshold. In contrast, by making an elastomer more elastic, e.g., by training through cyclic loading, the non-affine dissipation remains effective, and the limiting fracture energy is significantly higher than the threshold even when the hysteresis is negligible. The identification of the non-affine-dissipation mechanism paves the way to the development of new soft materials with both excellent elasticity and significant fracture toughness.

Fracture energy Non-affine deformation Polymer Threshold Viscoelasticity

English

First ; Corresponding

2-s2.0-85146580740

Scopus

Shenzhen Key Laboratory of Soft Mechanics & Smart Manufacturing,Department of Mechanics and Aerospace Engineering,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China

Liu，Yazhuo,Feng，Xianke,Hong，Wei. Non-affine dissipation in polymer fracture[J]. Extreme Mechanics Letters,2023,59.

Liu，Yazhuo,Feng，Xianke,&Hong，Wei.(2023).Non-affine dissipation in polymer fracture.Extreme Mechanics Letters,59.

Liu，Yazhuo,et al."Non-affine dissipation in polymer fracture".Extreme Mechanics Letters 59(2023).