Multi-step metamaterials with two phases of elastic and plastic deformation

2021 ◽  
pp. 114152
Author(s):  
Zhiqiang Meng ◽  
Zi Ouyang ◽  
Chang Qing Chen
2020 ◽  
pp. 14-24
Author(s):  
Francois Louchet

The main mechanical and physical quantities and concepts ruling deformation, fracture, and friction processes are recalled, with particular attention paid to the simplicity of the analysis, but without betraying the scientific validity of the arguments. We particularly discuss the difference between between elastic and plastic deformation, and quasistatic and dynamic loadings, essential in avalanche triggering mechanisms. The physical origin of Griffith’s rupture criterion that rules both fracture nucleation and propagation, and the transition between brittle and ductile failure processes, is thoroughly discussed. We also explain the physical meaning of the classical Coulomb’s friction law, showing why it can hardly apply to a non-conventional porous, brittle, and healable solid like snow.


1988 ◽  
Vol 32 ◽  
pp. 355-364 ◽  
Author(s):  
I. C. Noyan ◽  
L. T. Nguyen

AbstractOscillations jn "d" vs. sin2ψ plots are due to the inhomogeneous partitioning of strains within the diffracting volume. In polycrystalline specimens, such inhomogeneity can be caused by the elastic incompatibility of neighboring grains or by the inhoniogeneous partitioning of plastic deformation within the diffracting volume. There is, however, little work on the degree of inhomogeneity required to cause a given oscillation, and the relative contribution from the elastic and plastic deformation components to a given oscillation.


2005 ◽  
Vol 500-501 ◽  
pp. 655-662 ◽  
Author(s):  
Xavier Kleber ◽  
Aurélie Hug-Amalric ◽  
Jacques Merlin

In this work, we show that the measurement of the Barkhausen noise allows the residual stresses in each of the two phases of ferrite-martensite steels to be characterized. We have first studied the effect of a tensile and a compressive stress on the Barkhausen noise signature. We observed that for a ferrite-martensite steel, the application of a tensile stress increases the Barkhausen activity of the martensite and ferrite phases, whereas a compressive one reduces it. In a second time, we induced residual stresses by applying a plastic deformation to ferrite-martensite steels. After a tensile plastic deformation, we observed that (i) compressive residual stresses appear in ferrite, and (ii) tensile residual stresses appear in martensite. An opposite behavior is observed after a compressive plastic deformation. These results show that the Barkhausen noise measurement makes it possible to highlight in a nondestructive way the distribution of the stresses in each of the two phases of a ferrite-martensite steel. This result could be used to characterize industrial Dual- Phases steels that are plastically deformed during mechanical processes.


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