PIPE16 vs PIPE288: Ansys v.14 Tutorial Differences

[mechgen]

Hi,

How is PIPE288 element type different from its previous version PIPE16 (Ansys v. 14) ? I was reading a tutorial which modeled a cantilever beam with PIPE16 model using real constants to define the pipe thickness and outer thickness. But according to my software version PIPE288 does not require any real constants. So I had to assign those values using SECTYPE and SECDATA commands. The result I got was different from that of the tutorial. I would like to know why?

Thank You in advance!

 

[nvn]

mechgen: I think the PIPE288 versus PIPE16 answers should be virtually the same, in most cases, unless the cantilever is quite short, or perhaps the displacement is large. If you post your real constants, and your SECDATA, then perhaps someone might be able to check whether they are equivalent. Also, if you post the entire given problem (and given answer), then someone might be able to check the answer.

 

[thisishaoliang]

I am also learning the tutorials from University of Albert for this example. After defining the element type by pipe288, I defined the section in Preprocessor-Sections-Pipe-Add (details: Add pipe section with ID: 1, then Add or edit pipe section: section name: pipe1, pipe diameter: 25, wall thickness: 2). Then did everything else like the tutorial said. Finally I got almost the same result as in the tutorial.

PRINT U NODAL SOLUTION PER NODE

***** POST1 NODAL DEGREE OF FREEDOM LISTING *****

LOAD STEP= 0 SUBSTEP= 1
TIME= 1.0000 LOAD CASE= 0

THE FOLLOWING DEGREE OF FREEDOM RESULTS ARE IN THE GLOBAL COORDINATE SYSTEM

NODE UX UY UZ USUM
1 0.0000 0.0000 0.0000 0.0000
2 0.0000 -6.2066 0.0000 6.2066
3 0.0000 -0.15613E-01 0.0000 0.15613E-01
4 0.0000 -0.59714E-01 0.0000 0.59714E-01
5 0.0000 -0.13112 0.0000 0.13112
6 0.0000 -0.22863 0.0000 0.22863
7 0.0000 -0.35107 0.0000 0.35107
8 0.0000 -0.49725 0.0000 0.49725
9 0.0000 -0.66599 0.0000 0.66599
10 0.0000 -0.85609 0.0000 0.85609
11 0.0000 -1.0664 0.0000 1.0664
12 0.0000 -1.2956 0.0000 1.2956
13 0.0000 -1.5427 0.0000 1.5427
14 0.0000 -1.8064 0.0000 1.8064
15 0.0000 -2.0855 0.0000 2.0855
16 0.0000 -2.3789 0.0000 2.3789
17 0.0000 -2.6853 0.0000 2.6853
18 0.0000 -3.0036 0.0000 3.0036
19 0.0000 -3.3326 0.0000 3.3326
20 0.0000 -3.6711 0.0000 3.6711
21 0.0000 -4.0179 0.0000 4.0179
22 0.0000 -4.3718 0.0000 4.3718
23 0.0000 -4.7316 0.0000 4.7316
24 0.0000 -5.0962 0.0000 5.0962
25 0.0000 -5.4643 0.0000 5.4643
26 0.0000 -5.8349 0.0000 5.8349

MAXIMUM ABSOLUTE VALUES
NODE 0 2 0 2
VALUE 0.0000 -6.2066 0.0000 6.2066

 

[thisishaoliang]

Sorry, now I know what you mean. It is like, when we use pipe288, the calculated maximum tensile stress by bending is 63.8489 MPa, but it should be 64.9 MPa, like the tutorial said. :(

The detailed description about this example can be seen here:
http://www.mece.uAlberta.ca/tutorials/ansys/BT/Bike/Bike.html

Is there anyone who can help us? Thank you very much!