Comment on the Nanoindentation Protocol and its relation to nanoblitz

 For nanoblitz, we cannot set a exact depth value as we did in the std hardness protocol, but we can decrease the load to 0.2mN or so to reach around 50nm depth

Hakan Yavas:
    Yes, fast protocol, hardness and nanoblitz are here
Ryder Bolin:
    There is suppose to be more nano blitz load and disp
Hakan Yavas:
    Ok, I saw it
Ryder Bolin:
    You saw that data?
Hakan Yavas:
    By the way, you did not get any hardness measurements
Stefanos Papanikolaou:
    ?
Hakan Yavas:
    It seems that the tip did not touch the surface
Ryder Bolin:
    Yes we did
    For nano?
    Cause the hard protocol has it
    Never mind I see it. Could you explain to me why this happened?
Hakan Yavas:
    You only have the hardness up to 0.3nm
Ryder Bolin:
    I removed backlash every time I set something up. You can ask stefanos he was there
    Hakan look at the nano indenter protocol and see if you can find what's going on.


Hakan Yavas:
    I am checking it
    when did you calibrate the tip?
Stefanos Papanikolaou:
    Ryder?
Ryder Bolin:
    Maybe 2 months ago I believe
Stefanos Papanikolaou:
    before we moved the machine?
Ryder Bolin:
    After nano mechanics ran checks on silica remember.
Hakan Yavas:
    December 6th
    Wrong tip calibration may cause this
Ryder Bolin:
    Nano mechanics ran is a complete work up. I had the check functionality and noise
Hakan Yavas:
    ryder, to do a proper tip calibration please follow the routine from the manual page 71
Ryder Bolin:
    Okay I'll run another calibration
Hakan Yavas:
    as I stated previously you should redo the tip calibration after getting large batch of data- so we can get more reliable data. hardness is a function of indented tip area and software calculates stiffness etc. using this parameter. it is very crucial
    + before running a tip calibration please clean the silica surface to remove possible contaminations and dirts- this will increase the calibration efficiency
Ryder Bolin:
    Okay I'll take care of it.


Re-calculation before exporting::::

Stefanos Papanikolaou:
    il momento della verita
Hakan Yavas:
    Also exported
Stefanos Papanikolaou:
    Ryder?
Ryder Bolin:
    Show me
    No show me how you exported
Hakan Yavas:
    Ok
    Before exporting it I recalculated the results
    Did you see it
Ryder Bolin:
    Oh okay try that with load.
    I saw
    Okay it worked thanks
Hakan Yavas:
    That works right
Ryder Bolin:
    Yes!
Hakan Yavas:
    Great

Useful Info on LAMMPS:

Professor.....among the last four column 1st one is the z coordinate value. In our case it is a 2d simulation so this value is always zero.

The last three values are as following.......

"The final 3 nx,ny,nz values on a line of the Atoms entry are optional. LAMMPS only reads them if the "true flag" command is specified in the input command script. Otherwise they are initialized to 0 by LAMMPS. Their meaning, for each dimension, is that "n" box-lengths are added to xyz to get the atom's "true" un-remapped position. This can be useful in pre- or post-processing to enable the unwrapping of long-chained molecules which wind thru the periodic box one or more times. The value of "n" can be positive, negative, or zero. For 2-d simulations specify nz as 0"

link: http://lammps.sandia.gov/doc/2001/data_format.html 

This is what true flag command says.....

"read atom positions  and dump atom positions in one of 2 formats

• flag = 0 -> read/dump only atom positions (remapped to periodic box)
• flag = 1 -> dump atom positions plus integer box counts
• flag = 2 -> read atom positions plus integer box counts
• flag = 3 -> read/dump atom positions plus integer box counts

for each dimension, box count of "n" means add that many box lengths
  to get "true" un-remapped position, "n" can be positive, negative, or zero
 

Default = 0"

Welcome to the laboratory page of Stefanos Papanikolaou's research assistants. Every weekly to-do list will be posted here, as well as a recording of our latest projects and achievements.

Paper Deadline Target

• Indentation papers (2).
• Joshua Thibault's paper.Joshua Thibault
• Michalis Tzimas's paper.

The target for all 4 papers has been set to the end of March