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Fatigue-resistant polymer networks
Toughness of natural rubber measured under monotonic load is ~10,000 J/m2.
Fatigue threshold of natural rubber measured under cyclic load is ~50 J/m2.
The large difference is due to dissipation in the bulk.
@EnduricaWill @aljcrosby
Toughness of natural rubber measured under monotonic load is ~10,000 J/m2.
Fatigue threshold of natural rubber measured under cyclic load is ~50 J/m2.
The large difference is due to dissipation in the bulk.
@EnduricaWill @aljcrosby
Where does the threshold of 50 J/m2 come from? Lake-Thomas 1967 model.
Before a polymer chain breaks, every monomer of the chain is stretched near breaking.
When the chain snaps, only one bond breaks, but the energy of the entire chain is dissipated.
https://doi.org/10.1098/rspa.1967.0160">https://doi.org/10.1098/r...
Before a polymer chain breaks, every monomer of the chain is stretched near breaking.
When the chain snaps, only one bond breaks, but the energy of the entire chain is dissipated.
https://doi.org/10.1098/rspa.1967.0160">https://doi.org/10.1098/r...
Stiffness-threshold conflict and a resolution.
High fatigue threshold requires a polymer network to have a long chain, but a network of long chains has low stiffness.
This paper describes a resolution of this conflict.
@DRudolfKing @CretonCost
https://doi.org/10.1115/1.4044897">https://doi.org/10.1115/1...
High fatigue threshold requires a polymer network to have a long chain, but a network of long chains has low stiffness.
This paper describes a resolution of this conflict.
@DRudolfKing @CretonCost
https://doi.org/10.1115/1.4044897">https://doi.org/10.1115/1...
The Lake-Thomas model exemplifies a general concept: elastic dissipater.
A structural unit is elastically stretched.
When the unit breaks, the energy of the entire unit dissipates.
An elastic dissipater reaches a fatigue threshold above 1000 J/m2.
https://doi.org/10.1016/j.mattod.2019.08.009">https://doi.org/10.1016/j...
A structural unit is elastically stretched.
When the unit breaks, the energy of the entire unit dissipates.
An elastic dissipater reaches a fatigue threshold above 1000 J/m2.
https://doi.org/10.1016/j.mattod.2019.08.009">https://doi.org/10.1016/j...
This idea of elastic dissipater has been used to make fatigue-resistant elastomers
https://doi.org/10.1016/j.jmps.2019.103751
https://doi.org/10.1016/j... href="https://twitter.com/RobibAllarini">@RobibAllarini @ykutsovsky
https://doi.org/10.1016/j.jmps.2019.103751
Elastic dissipater enables an elastomer to have both high toughness and low hysteresis. https://doi.org/10.1073/pnas.1821420116">https://doi.org/10.1073/p...
Here is a review on fatigue of hydrogels.
@RuobingB @DrJiaweiYang
https://doi.org/10.1016/j.euromechsol.2018.12.001">https://doi.org/10.1016/j...
@RuobingB @DrJiaweiYang
https://doi.org/10.1016/j.euromechsol.2018.12.001">https://doi.org/10.1016/j...
Here is an iMechanica ( @iMechanica2006) Journal Club led by @lin_shaoting and @ProfZhaoMIT on fatigue-resistant hydrogels.
https://imechanica.org/node/24333 ">https://imechanica.org/node/2433...
https://imechanica.org/node/24333 ">https://imechanica.org/node/2433...
This paper shows that tough hydrogel adhesion is susceptible to fatigue.
https://doi.org/10.1016/j.eml.2019.100601
https://doi.org/10.1016/j... href="https://twitter.com/Ljycanon">@Ljycanon @chenchao04
https://doi.org/10.1016/j.eml.2019.100601
This paper shows that long-chain network adhesion has high fatigue threshold.
https://doi.org/10.1016/j.eml.2020.100813
https://doi.org/10.1016/j... href="https://twitter.com/HangYan95173747">@HangYan95173747 @Baohong_Chen @EnduricaWill @CretonCost
https://doi.org/10.1016/j.eml.2020.100813
In getting ready for a graduate course, I add a crosslink between this thread and an iMechaanica thread on hydrogel fatigue.
https://imechanica.org/node/23127
Please">https://imechanica.org/node/2312... add ideas and links.
@RuobingB @DrJiaweiYang @ProfZhaoMIT @lin_shaoting @CretonCost @EnduricaWill @jasongsteck @ToLiTeng
https://imechanica.org/node/23127
Please">https://imechanica.org/node/2312... add ideas and links.
@RuobingB @DrJiaweiYang @ProfZhaoMIT @lin_shaoting @CretonCost @EnduricaWill @jasongsteck @ToLiTeng
