Axisymmetric Analysis/ Input File Issue

[qasim]

Dear FEAP Team,

I wrote an input file for axisymmetric analysis. A thick cylinder under internal pressure (Example 9.2) from the Book "A First Course in the Finite Element Method" by Daryl L. Logan in FEAP.
And I try to compare my Matlab analysis results and FEAP results with the solution given in the book.
Matlab results are identical with the solution given in the book but FEAP gives different results.

I attached FEAP input file and results of comparison here.

would you please let me know where is the error in my FEAP Input File?

Best regards,
Qasim

[Prof. R.L. Taylor]

Post your input file.

remember feap does one radian not 2*pi -- but answers differ by more than that.

[Prof. R.L. Taylor]

Sorry, i have the file and will check it

[Prof. R.L. Taylor]

The nodal forces in feap should be 0.125 at the two vertex nodes (no 2*pi).

Feap is currently useing a 3-point quadrature for the element.  So answers may still be different.  If you switch to a 1-point then the answers are the same.

We will review why the 3-points (originally it was for the inertia terms where 1- point is not adequate).  But this is now moved to a separate routine which uses its own quadrature setting.