uniaxial tension followed by shear

[Schandra]

Dear all,

I am trying on a simple problem of applying uniaxial tension on a unit cube and then subsequently shearing it.
I am successful in applying shear in the first step but in the second step I get shear+tension (am unable to restrict the first step).
Can you please help me in identifying my mistake.

Warm Regards,
Chandra

[Prof. R.L. Taylor]

It looks like the displacements at the mid-height are not moving correctly.

I would suggest you use feap graphics to check the mesh at each stage to make sure you have set the correct boundary restraints.  You can do this by putting INTEractive commands at solution stages and then look at the ID array and plot results

This is a small problem you do not need to use PARDiso either for this problem or paraview.

[xuehanbing]

Dear Schandra:
     I want to ask you how to apply shear in the first step and in the second step I get shear+tension.
    Thank you.
    xuehanbing.

[Schandra]

Thanks for the comments Prof. Taylor, I shall do so.

[Yaakov]

xuehanbing,

just look for the post about boundary change problem in our feap forum.

& for pure shear loading in 2 or 3 D (this case is not pure shear), we shall define the Neuman & Dirichlet BC in input file carefully.

for pure shear loading applicaitons you may see some new articles by De Borst et al.


Best,
Yaakov

Dear Schandra:
     I want to ask you how to apply shear in the first step and in the second step I get shear+tension.
    Thank you.
    xuehanbing.

[fethio]

This post was interesting for me because it urged me to give the input file a try, then I saw it was using an isogeometric  type.

However, it didn't work. Upon running the original input file I got the error:

*ERROR* PNUMS: Problem size does not permit a solution:
         Number of nodes         =         6
         Number of elements      =         0
         Number of material sets =         1


Hmm, I guess I didn't compile FEAP the way it was supposed to be, in order for the NURb, etc commands to work.

[FEAP_Admin]

You need to compile the program in the igafeap directory.

[fethio]

I suppose it is necessary to add the line
   (cd igafeap; make archive)
to the Makefile is enough?

[Prof. R.L. Taylor]

You need to make "ifeap",  probably just "make" is enough once you are in the igafeap directory.  The executable is in "igafeap/main"

[fethio]

Thank you Prof. Taylor.