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This paper describes a method to print laminates of hard and soft metals. The report on mechanics is light. Does the laminate achieve high strength by de-concentrating stress through shear lag? @SammyHassan_ @Tengh_Yin @Junsoo_twit https://www.nature.com/articles/s41586-020-2409-3
Here is news report of the paper by @Giulia_Pacc: https://www.nature.com/articles/s41578-020-0219-8
Is Damascus steel fatigue-resistant? Likely. At a crack front, the soft layer undergoes ratcheting deformation, and de-concentrates stress in the hard layer. See an old paper on crawling.
https://suo.seas.harvard.edu/files/suo/files/114.pdf
https://suo.seas.harvard.edu/files/suo/files/114.pdf
In metals, hard and soft are measured by yield strength. In elastomers, hard and soft are measured by modulus. There is some analogy.
Here is a recent paper on fatigue-resistant elastomers through stress de-concentration.
https://suo.seas.harvard.edu/files/suo/files/417.pdf
Here is a recent paper on fatigue-resistant elastomers through stress de-concentration.
https://suo.seas.harvard.edu/files/suo/files/417.pdf
The hard/soft microstructure exists in many materials. An example is PVA hydrogels. @lin_shaoting @ProfZhaoMIT
@RuobingB @Ljycanon @DrJiaweiYang
http://zhao.mit.edu/wp-content/uploads/2019/05/118.pdf
https://suo.seas.harvard.edu/files/suo/files/396.pdf
@RuobingB @Ljycanon @DrJiaweiYang
http://zhao.mit.edu/wp-content/uploads/2019/05/118.pdf
https://suo.seas.harvard.edu/files/suo/files/396.pdf
Also see a journal club on fatigue-resistant hydrogels by
@lin_shaoting and @ProfZhaoMIT
https://imechanica.org/node/24333
@lin_shaoting and @ProfZhaoMIT
https://imechanica.org/node/24333
Metallic laminates vs. elastomeric laminates.
Similarity: soft phase de-concentrates stress in hard phase.
Difference: metals are plastic, but elastomers are elastic.
Cyclic load may cause incremental deformation at the crack front in metals, but may not in elastomers.
Similarity: soft phase de-concentrates stress in hard phase.
Difference: metals are plastic, but elastomers are elastic.
Cyclic load may cause incremental deformation at the crack front in metals, but may not in elastomers.
Stress de-concentration also operates in ceramic composites. The fiber/matrix interface is weak, which de-concentrates stress in the fiber.
See a discussion in the paragraph just before Conclusion. https://suo.seas.harvard.edu/files/suo/files/398.pdf
See a discussion in the paragraph just before Conclusion. https://suo.seas.harvard.edu/files/suo/files/398.pdf
For stress de-concentration across many length scales, see Fig. S9.
A polymer network is an elastic dissipater. De-concentrate stress over an entire chain.
Lattices are also elastic dissipaters.
https://www.pnas.org/content/pnas/suppl/2019/03/07/1821420116.DCSupplemental/pnas.1821420116.sapp.pdf
A polymer network is an elastic dissipater. De-concentrate stress over an entire chain.
Lattices are also elastic dissipaters.
https://www.pnas.org/content/pnas/suppl/2019/03/07/1821420116.DCSupplemental/pnas.1821420116.sapp.pdf
Ahmed Elbanna ( @MCSlab_uiuc) describes another example of stress de-concentration. https://www.sciencedirect.com/science/article/pii/S2352431619300070?via%3Dihub
In this 2012 PRL, Shuman Xia and coworkers demonstrated tough adhesion through heterostructure.
The effect can also be interpreted as stress de-concentration. https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.108.196101
The effect can also be interpreted as stress de-concentration. https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.108.196101
