Hi,
I do not know if someone else has also encountered this but recently in ANSYS 2019R3 I have experienced different reaction force values (at the displacement boundary condition) for a pressure vessel with two different mesh element order under mesh tab of workbench- 1)program controlled and 2) quadratic
The part that I am analyzing is a tube (pressure retaining) with bolted flanges at the top. I modeled beams for the bolts as line bodies.
Only difference that I could see in the solution information for the two options was that in quadratic mesh order BEAM189 elements was selected with suggested keyopts set and with program controlled mesh order the program used BEAM188 elements.
Also the following warning/note was seen with BEAM188.
*** NOTE *** CP = 14.797 TIME= 17:40:12
Internal nodes from 669410 to 669433 are created.
24 internal nodes are used for quadratic and/or cubic options of
BEAM188, PIPE288, and/or SHELL208.
Only pressure load was applied and preload was suppressed. The area on which the pressure was applied was 2.2718e-3 m2 and pressure was 3.4e6 Pa. The reaction force should come to be 7724 N but it is coming to be 6657N with program controlled option of mesh order under mesh tab whereas for quadratic option of mesh order the reaction force is in good agreement with the applied load.
Why there is such a difference of force reaction between these two options ?? Is it a bug or am I missing something?
Shiraz
Sr. Engineer
I do not know if someone else has also encountered this but recently in ANSYS 2019R3 I have experienced different reaction force values (at the displacement boundary condition) for a pressure vessel with two different mesh element order under mesh tab of workbench- 1)program controlled and 2) quadratic
The part that I am analyzing is a tube (pressure retaining) with bolted flanges at the top. I modeled beams for the bolts as line bodies.
Only difference that I could see in the solution information for the two options was that in quadratic mesh order BEAM189 elements was selected with suggested keyopts set and with program controlled mesh order the program used BEAM188 elements.
Also the following warning/note was seen with BEAM188.
*** NOTE *** CP = 14.797 TIME= 17:40:12
Internal nodes from 669410 to 669433 are created.
24 internal nodes are used for quadratic and/or cubic options of
BEAM188, PIPE288, and/or SHELL208.
Only pressure load was applied and preload was suppressed. The area on which the pressure was applied was 2.2718e-3 m2 and pressure was 3.4e6 Pa. The reaction force should come to be 7724 N but it is coming to be 6657N with program controlled option of mesh order under mesh tab whereas for quadratic option of mesh order the reaction force is in good agreement with the applied load.
Why there is such a difference of force reaction between these two options ?? Is it a bug or am I missing something?
Shiraz
Sr. Engineer
