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RBE3 Issue
Forum: MYSTRAN
Last Post: Jon
10-05-2021, 11:57 PM
» Replies: 4
» Views: 188
Failure Theory values
Forum: MYSTRAN
Last Post: Admin
10-01-2021, 04:21 AM
» Replies: 1
» Views: 103
MYSTRAN Solid Element Buc...
Forum: MYSTRAN
Last Post: ceanwang
09-10-2021, 05:42 AM
» Replies: 2
» Views: 329
Gmsh
Forum: Pre/Post Processors
Last Post: ceanwang
08-15-2021, 12:51 AM
» Replies: 10
» Views: 5,050
error in beam analysis
Forum: MYSTRAN
Last Post: ZacharyALerner
08-05-2021, 03:17 AM
» Replies: 6
» Views: 721
tetra10 from pyNastran do...
Forum: MYSTRAN
Last Post: bernd
08-03-2021, 04:31 PM
» Replies: 5
» Views: 551
New User Bernd
Forum: MYSTRAN
Last Post: bernd
07-26-2021, 03:03 PM
» Replies: 2
» Views: 345
Weired issue with CBUSHES...
Forum: MYSTRAN
Last Post: drbillc
07-15-2021, 02:51 PM
» Replies: 2
» Views: 420
Ansible Role to install M...
Forum: MYSTRAN
Last Post: numenic
04-19-2021, 09:41 PM
» Replies: 0
» Views: 705
Python Neutral Parse
Forum: Pre/Post Processors
Last Post: numenic
04-16-2021, 08:02 AM
» Replies: 0
» Views: 466

 
  Failure Theory values
Posted by: fmjs - 09-30-2021, 02:06 PM - Forum: MYSTRAN - Replies (1)

Hello,

I'm using Mystran to test some composite structures, and I need the value of the Failure Theory layer by layer.

Is it possible to output the values for the Failure Theory index for all elements/layer? From the output, one can only get min and max at the summary.

Regards,
Filipe Silva

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  RBE3 Issue
Posted by: Jon - 09-28-2021, 04:38 AM - Forum: MYSTRAN - Replies (4)

I came across and issue with the RBE3 element. I have already emailed Bill about the issue, but I thought I would post here for the benefit of the rest pf the community.

I am using a RBE3 to distribute load at a bolted joint. The joint is in thin sheet metal structure so I do not want the fasteners to take out of plane load. I used the following RBE3 to accomplish this.

RBE3          17              17  123456   0.189      13    9901   0.189+     
+             13    9902   0.189      13    9903   0.189      13    9904+     
+          0.189      12    9905   0.189      12    9906   0.189      12+     
+           9907   0.189      12    9908   0.189      12    9909   0.189+     
+             12    9910   0.189      12    9911   0.189      12    9912+     
+          0.189      13    9913   0.189      13    9914   0.189      13+     
+           9915   0.189      13    9916

When I run this through MYSTRAN the SPC forces are not equal and opposite the applied loads. The SPC forces in the Y and Z directions are half of what they should be.  It appears that the RBE3 is incorrectly calculating the weighted average when one or more independent nodes are not effective in all three translational DOF. To check this I changed the RBE3 to have Ci = 123 for every independent node. I also ran my original model through NXNASTRAN. In both cases the SPC forces were equal and opposite to the applied loads.

I have attached copies of the BDF and F06 files for the original run and the run with Ci = 123.

Cheers.

Jon



Attached Files
.txt   BoltGroup.bdf.txt (Size: 4.21 KB / Downloads: 2)
.txt   BoltGroup.F06.txt (Size: 19.57 KB / Downloads: 1)
.txt   BoltGroup_C123.bdf.txt (Size: 4.21 KB / Downloads: 0)
.txt   BoltGroup_C123.F06.txt (Size: 19.57 KB / Downloads: 0)
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  error in beam analysis
Posted by: bernd - 08-03-2021, 06:39 PM - Forum: MYSTRAN - Replies (6)

attached two simple cantilever analysises. One runs the other with slighlty greater cross section does give all zero. I  do not know why nor can I really read the logs. What do I need to look for? Can someon confirm the problem an may be give some hints what went wrong.

cheers bernd


.txt   Mesh_not_ok.bdf.txt (Size: 5.29 KB / Downloads: 7)


.txt   Mesh_not_ok.F06.txt (Size: 31.88 KB / Downloads: 4)


.txt   Mesh_ok.bdf.txt (Size: 5.29 KB / Downloads: 6)


.txt   Mesh_ok.F06.txt (Size: 30.06 KB / Downloads: 1)

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  MYSTRAN Solid Element Buckling
Posted by: drbillc - 07-30-2021, 02:35 AM - Forum: MYSTRAN - Replies (2)

I've recently added code to MYSTRAN for buckling/differential stiffness for the 6 solid elements: HEXA (8 and 20 node), PENTA (6 and 15 node) and TETRA (4 and 10 node). Attached are the results of a study of the accuracy of the code. A beam of dimensions 1"x1"x40" was modeled with each of the 3D solid elements and results are shown for the convergence to the beam critical buckling load vs mesh size. It is seen that all 6 elements are quite accurate, even for a fairly coarse mesh. I would appreciate anyone trying out these elements, especially with some element distortion, to see if the accuracy holds up



Attached Files
.pdf   MYSTRAN 3D Solid Element Buckling Study.pdf (Size: 310.33 KB / Downloads: 8)
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  tetra10 from pyNastran do not work with Mystran
Posted by: bernd - 07-22-2021, 12:48 PM - Forum: MYSTRAN - Replies (5)

tetra10 from pyNastran do not work with Mystran. the files are attached ...

this is what I used in pyNastran

Code:
model.add_grid(1, [8000.0, 1000.0, 0.0])
...

model.add_ctetra(147, 1, [23, 12, 22, 42, 110, 122, 68, 174, 192, 184])



This is what the solver Mystran said ...

Code:
*ERROR  1928: ELEMENT      149, TYPE TETRA10 , HAS JACOBIAN LESS THAN OR EQUAL TO ZERO ( = -7.3E+08). BAD GEOMETRY

...


.txt   Box_Mesh.bdf.txt (Size: 21.74 KB / Downloads: 3)

.txt   Box_Mesh.py.txt (Size: 18.33 KB / Downloads: 3)

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  New User Bernd
Posted by: bernd - 07-22-2021, 12:44 PM - Forum: MYSTRAN - Replies (2)

Hi there,

just wanted to say hello. I am from FreeCAD FEM workbench projekt. I started to play with Mystran. For sure I will have questions ...

Depending on my time range there will be more or less questions ... 


cheers bernd

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  Weired issue with CBUSHES (cont)
Posted by: numenic - 07-12-2021, 03:29 PM - Forum: MYSTRAN - Replies (2)

hello Forum,

I'm referring to this issue https://github.com/dr-bill-c/MYSTRAN/issues/12

The very strange thing is that I do not get the same F06 results that DrBill! how can it be? Compilation issue? Configuration?

I have the same issue with 12.3 and 12.4.

Thanks in advance.
numenic / toto

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  Ansible Role to install MYSTRAN
Posted by: numenic - 04-19-2021, 09:41 PM - Forum: MYSTRAN - No Replies

I pusblished here (https://framagit.org/numenic/mystran_instl_ansible_role) a small Ansible role for installing Mystran. I use it under Ubuntu, but it should work *at least* under Debian too.

It basically:

* check and install "gcc", "gfortran", "make", "git", "f2c"
* under Ubuntu: install "libssl-deb" (necessaty tom compile CMAKE)
* git clone or git pull CMAKE sources
* compile CMAKE if git repo has changed
* git clone or git pull Mystran sources
* compile Mystran if git repo has changed

Do not hesitate to give me your feedback and issues.

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  Python Neutral Parse
Posted by: numenic - 04-16-2021, 08:02 AM - Forum: Pre/Post Processors - No Replies

I wrote a lightweight python femap neutral file parser to ease automatic post-processing:

It's available on pypi: https://pypi.org/project/femap-neutral-parser/
repository: https://framagit.org/numenic/femap_neutral_parser/

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  FEMAP neutral improvements
Posted by: numenic - 04-09-2021, 03:44 PM - Forum: Pre/Post Processors - Replies (7)

Writing a FEMAP neutral parser, I met some some quirks with the file generated by MYSTRAN (v12.1). This thread aims to collect them. Please tell me if I need to split this thread per subject or question!

I'll begin with this a simpleCBAR + CBUSH model. The attached archive provides the following files:

* "bulk_model_TC3.nas": the BULK file
* "mystran_00.NEU": the MYSTRAN output
* "FEMAP_v8.2.neu": the FEMAP v8.2 output
* "FEMAP_v2020-1-0.neu": the FEMAP v2020.1 output

First remark: Block451 is used by both MYSTRAN and FEMAP8.2 to collect results, but is deprecated in later versions in favor of block 1051.

Block451: titles used by MYSTRAN do not match FEMAP titles. This makes harder to write "solver-agnostic" parsers. From the uploaded files, here is the list with mismatch and missing :

That's all for now! thanks for reading and happy MYSTRANning !

Code:
| FEMAP vector Title        | FEMAP vector ID | MYSTRAN vector Title     | MYSTRAN vector ID |
|---------------------------+-----------------+--------------------------+-------------------|
| Total Translation         | 1               | RSS translation          | 10001             |
| T1 Translation            | 2               | T1  translation          | 10002             |
| T2 Translation            | 3               | T2  translation          | 10003             |
| T3 Translation            | 4               | T3  translation          | 10004             |
| Total Rotation            | 5               | RSS rotation             | 10005             |
| R1 Rotation               | 6               | R1  rotation             | 10006             |
| R2 Rotation               | 7               | R2  rotation             | 10007             |
| R3 Rotation               | 8               | R3  rotation             | 10008             |
| Total Applied Force       | 41              | RSS applied force        | 20001             |
| T1 Applied Force          | 42              | T1  applied force        | 20002             |
| T2 Applied Force          | 43              | T2  applied force        | 20003             |
| T3 Applied Force          | 44              | T3  applied force        | 20004             |
| Total Applied Moment      | 45              | RSS applied moment       | 20005             |
| R1 Applied Moment         | 46              | R1  applied moment       | 20006             |
| R2 Applied Moment         | 47              | R2  applied moment       | 20007             |
| R3 Applied Moment         | 48              | R3  applied moment       | 20008             |
| Total Constraint Force    | 51              | RSS SPC force            | 30001             |
| T1 Constraint Force       | 52              | T1  SPC force            | 30002             |
| T2 Constraint Force       | 53              | T2  SPC force            | 30003             |
| T3 Constraint Force       | 54              | T3  SPC force            | 30004             |
| Total Constraint Moment   | 55              | RSS SPC moment           | 30005             |
| R1 Constraint Moment      | 56              | R1  SPC moment           | 30006             |
| R2 Constraint Moment      | 57              | R2  SPC moment           | 30007             |
| R3 Constraint Moment      | 58              | R3  SPC moment           | 30008             |
| Total MultiPoint Force    | 151             | na                       | na                |
| T1 MultiPoint Force       | 152             | na                       | na                |
| T2 MultiPoint Force       | 153             | na                       | na                |
| T3 MultiPoint Force       | 154             | na                       | na                |
| Total MultiPoint Moment   | 155             | na                       | na                |
| R1 MultiPoint Moment      | 156             | na                       | na                |
| R2 MultiPoint Moment      | 157             | na                       | na                |
| R3 MultiPoint Moment      | 158             | na                       | na                |
| Total Summed GPForce      | 161             | na                       | na                |
| T1 Summed GPForce         | 162             | na                       | na                |
| T2 Summed GPForce         | 163             | na                       | na                |
| T3 Summed GPForce         | 164             | na                       | na                |
| Total Summed GPMoment     | 165             | na                       | na                |
| R1 Summed GPMoment        | 166             | na                       | na                |
| R2 Summed GPMoment        | 167             | na                       | na                |
| R3 Summed GPMoment        | 168             | na                       | na                |
| Total Applied GPForce     | 171             | na                       | na                |
| T1 Applied GPForce        | 172             | na                       | na                |
| T2 Applied GPForce        | 173             | na                       | na                |
| T3 Applied GPForce        | 174             | na                       | na                |
| Total Applied GPMoment    | 175             | na                       | na                |
| R1 Applied GPMoment       | 176             | na                       | na                |
| R2 Applied GPMoment       | 177             | na                       | na                |
| R3 Applied GPMoment       | 178             | na                       | na                |
| Total Constraint GPForce  | 181             | na                       | na                |
| T1 Constraint GPForce     | 182             | na                       | na                |
| T2 Constraint GPForce     | 183             | na                       | na                |
| T3 Constraint GPForce     | 184             | na                       | na                |
| Total Constraint GPMoment | 185             | na                       | na                |
| R1 Constraint GPMoment    | 186             | na                       | na                |
| R2 Constraint GPMoment    | 187             | na                       | na                |
| R3 Constraint GPMoment    | 188             | na                       | na                |
| Bar EndA Plane1 Moment    | 3000            | BAR EndA Plane1 Moment   | 50201             |
| Bar EndA Plane2 Moment    | 3001            | BAR EndA Plane2 Moment   | 50203             |
| Bar EndB Plane1 Moment    | 3002            | BAR EndB Plane1 Moment   | 50202             |
| Bar EndB Plane2 Moment    | 3003            | BAR EndB Plane2 Moment   | 50204             |
| Bar EndA Pl1 Shear Force  | 3004            | BAR EndA Pl1 Shear Force | 50205             |
| Bar EndA Pl2 Shear Force  | 3005            | BAR EndA Pl2 Shear Force | 50207             |
| Bar EndA Axial Force      | 3008            | BAR EndA Axial Force     | 50209             |
| Bar EndA Torque           | 3010            | BAR EndA Torque          | 50211             |
| Bar EndA Pt1 Bend Stress  | 3075            | BAR EndA Pt1 Comb Stress | 60301             |
| Bar EndA Pt2 Bend Stress  | 3076            | BAR EndA Pt2 Comb Stress | 60303             |
| Bar EndA Pt3 Bend Stress  | 3077            | BAR EndA Pt3 Comb Stress | 60305             |
| Bar EndA Pt4 Bend Stress  | 3078            | BAR EndA Pt4 Comb Stress | 60307             |
| Bar EndB Pt1 Bend Stress  | 3083            | BAR EndB Pt1 Comb Stress | 60302             |
| Bar EndB Pt2 Bend Stress  | 3084            | BAR EndB Pt2 Comb Stress | 60304             |
| Bar EndB Pt3 Bend Stress  | 3085            | BAR EndB Pt3 Comb Stress | 60306             |
| Bar EndB Pt4 Bend Stress  | 3086            | BAR EndB Pt4 Comb Stress | 60308             |
| Bar EndA Axial Stress     | 3107            | na                       | na                |
| Bar EndA Max Comb Stress  | 3109            | BAR EndA Max Stress      | 60309             |
| Bar EndA Min Comb Stress  | 3110            | BAR EndA Min Stress      | 60311             |
| Bar EndB Max Comb Stress  | 3111            | BAR EndB Max Stress      | 60310             |
| Bar EndB Min Comb Stress  | 3112            | BAR EndB Min Stress      | 60312             |
| Bar Tension M.S.          | 3113            | na                       | na                |
| Bar Compression M.S.      | 3114            | na                       | na                |
| Bush X Force              | 3774            | na                       | na                |
| Bush Y Force              | 3775            | na                       | na                |
| Bush Z Force              | 3776            | na                       | na                |
| Bush X Moment             | 3777            | na                       | na                |
| Bush Y Moment             | 3778            | na                       | na                |
| Bush Z Moment             | 3779            | na                       | na                |
| Bush TX Stress            | 3780            | na                       | na                |
| Bush TY Stress            | 3781            | na                       | na                |
| Bush TZ Stress            | 3782            | na                       | na                |
| Bush RX Stress            | 3783            | na                       | na                |
| Bush RY Stress            | 3784            | na                       | na                |
| Bush RZ Stress            | 3785            | na                       | na                |
| Elem C1 T1 GPForce        | 85000           | na                       | na                |
| Elem C1 T2 GPForce        | 85001           | na                       | na                |
| Elem C1 T3 GPForce        | 85002           | na                       | na                |
| Elem C1 R1 GPMoment       | 85003           | na                       | na                |
| Elem C1 R2 GPMoment       | 85004           | na                       | na                |
| Elem C1 R3 GPMoment       | 85005           | na                       | na                |
| Elem C2 T1 GPForce        | 85010           | na                       | na                |
| Elem C2 T2 GPForce        | 85011           | na                       | na                |
| Elem C2 T3 GPForce        | 85012           | na                       | na                |
| Elem C2 R1 GPMoment       | 85013           | na                       | na                |
| Elem C2 R2 GPMoment       | 85014           | na                       | na                |
| Elem C2 R3 GPMoment       | 85015           | na                       | na                |
| na                        | na              | BAR EndB Pl1 Shear Force | 50206             |
| na                        | na              | BAR EndB Pl2 Shear Force | 50208             |
| na                        | na              | BAR EndB Axial Force     | 50210             |
| na                        | na              | BAR EndB Torque          | 50212             |



Attached Files
.zip   mystran_femap_q1.zip (Size: 17.52 KB / Downloads: 2)
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