Christine Heera Ahn, Zheqi Chen, Xianyang Bao, Zhigang Suo
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引用次数: 0
Abstract
We investigate fatigue crack growth in a polymer glass in which polymer chains are long and not crosslinked. Atoms bind by forces of two types: covalent bonds between repeat units along a chain, which resist chain scission, and noncovalent interactions between the chains, which resist chain slip. The covalent bonds are much stronger than the noncovalent interactions. When a crack impinges on a long chain, the chain slips and transmits tension over a segment of the chain. When the chain breaks at a single covalent bond, the energy stored in the segment dissipates. This molecular picture suggests a hypothesis: the fatigue threshold increases as the yield strength decreases. We analyze this hypothesis by developing a shear-lag model. We test the hypothesis by using high-molecular-weight poly(methyl methacrylate), and by modifying noncovalent interactions with plasticizers.
期刊介绍:
Soft Matter is an international journal published by the Royal Society of Chemistry using Engineering-Materials Science: A Synthesis as its research focus. It publishes original research articles, review articles, and synthesis articles related to this field, reporting the latest discoveries in the relevant theoretical, practical, and applied disciplines in a timely manner, and aims to promote the rapid exchange of scientific information in this subject area. The journal is an open access journal. The journal is an open access journal and has not been placed on the alert list in the last three years.