Lysmer in 2D vs 3D

[Dr. Ahmad Chihadeh]

Dear Colleagues,

I run example similar to the one provided here (http://feap.berkeley.edu/wiki/index.php?title=Lysmer-Kuhlemeyer), in 2D and in 3D.
However in 3D the result is not as good as in 2D. Note that I added a multiply by 'xsj' on  the definition of 'shpab'.
I attached the input files and the result.

Best regards,
Ahmad

[Dr. Ahmad Chihadeh]

I think this is because in 3D, xsj is multiplied by facp and facs

!         Velocity factors
          facp = d(15)*d(3)*d(11)*xsj    ! a*rho*V_p
          facs = d(16)*d(3)*d(12)*xsj    ! b*rho*V_s


and then it is also mutiplied by qq

!         Flux
          qq( : ) = (aa(:,1)*vv(1) + aa(:,2)*vv(2) + aa(:,3)*vv(3))*xsj

[Prof. R.L. Taylor]

I would suggest doing a 2-d like problem with a 3-d slice to find the possible coding error.

[Prof. R.L. Taylor]

Sorry after looking at your input files that is what you did.

There seems to be an extra xsj in the 3-d.  I removed the 'xsj' off the face & face terms and seem to get the same answer with both your files.   Hopefully this will help you.

[Prof. R.L. Taylor]

One other thing.  You should not need a MASS matrix in your batch file unless you are doing an Eigen analysis or an explicit time analysis.  For fear elements you can set the mass type in the MATErial set data.

[Dr. Ahmad Chihadeh]

Thank you Professor.
regarding the MASS, if I delete

MASS,CONSistent

from the input file, it does not work and I get

-> ERROR: ABC can not be used in static analysis

although there is still

BATC
TRANS,NEWM, 0.25, 0.5
END

in the input file.

[Prof. R.L. Taylor]

The need to include the MASS is a bug that will be corrected in the next release.