I have perform local stress calculation using stress/atom NULL virial command for the region assigned near crack.
how to calculate the volume of local region?
But need some comments on local stress calculation using Lammps.
Kindly also help me for calculating J integral for crack ...in MD using Lammps.
Hello,
"how to calculate the volume of local region?"
I think you could use compute voronoi(per atom) with the flag reduce/sum to get the volume for a geometric region. But, for this you require to compile with the Voronoi package.
"But need some comments on local stress calculation using Lammps."
Can you please elaborate what you mean by need for comments.
Please find the following references to better understand this concept
"The construction and application of an atomistic J-integral via Hardy estimates of continuum fields" Jones et al.
"An atomistic J-integral at finite temperature based on Hardy estimates of continuum fields" Jones et al.
"The application of an atomistic J-integral to a ductile crack" Zimmerman et al.
Hope that helps.
Ilaksh
thank you so much Ilaksh Adlakha for your kind help.
"But need some comments on local stress calculation using Lammps."
By saying above statement, I mean that for local stress calculation whether I should use only stress/atom command or stress/atom with virial keyword.....If possible please suggest some relevant literature
The choice of whether you need the virial or virial+kinetic contribution for stress/atom is something that is probably dictated by the temperature at which the simulations are being performed. However, a word of caution the Virial theorem is accurate representation of mechanical stress at the atomic level only for a few scenarios.
Please refer for details: "Calculation of stress in atomistic simulation" Zimmerman et al.
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