Hello,
I'm trying to perform a structural check of an item before load-out.
The item is fixed on nodes *S1 to *S4.
The overall weight of the ITEM is 1569 tons
---
+++ F O R C E S A C T I N G O N I T E M +++ ================================================= Process is DEFAULT: Units Are Degrees, Meters, and M-Tons Unless Specified Results Are Reported In Body System Type of Force X Y Z MX MY MZ ------------------ --------- --------- --------- --------- --------- --------- Weight 0.00 0.00 -1568.65 0 23888 0 Inertia 0.00 0.00 1568.65 0 -23887 0 ======= ======= ======= ======= ======= ======= Total 0.00 0.00 0.00 0 0 0
+++ F O R C E S A C T I N G O N I T E M +++
=================================================
Process is DEFAULT: Units Are Degrees, Meters, and M-Tons Unless Specified
Results Are Reported In Body System
Type of Force X Y Z MX MY MZ
------------------ --------- --------- --------- --------- --------- ---------
Weight 0.00 0.00 -1568.65 0 23888 0
Inertia 0.00 0.00 1568.65 0 -23887 0
======= ======= ======= ======= ======= =======
Total 0.00 0.00 0.00 0 0 0
The weight is supported on 4 legs (B1 to B4), and is practically centered, so each leg support point should have a reaction equal to 1569 ton /4 = 392 ton.
But the axial load computed by moses on each leg end is 307 ton.
+++ B E A M L O A D S T A N D A R D +++ =========================================== Units Are MPA, Degrees, Meters, and M-Tons Unless Specified Forces For Most Severe Load Case with Axial Load Greater Than 0 % Dist Axial /------ Shear -----/ /---- Bending ----/ Pressure Element /-- Node Names -/ Class Case From A Load Y Z Torque Y Z -------- -------- -------- -------- -------- --------- --------- --------- --------- --------- --------- --------- --------- B1 *DT1 *S1 ~BEAM SW 100.00 -306.51 4.71 -7.64 -0.00 -57.55 -34.49 0.0000 B2 *DT2 *S2 ~BEAM SW 100.00 -306.51 4.71 7.64 0.00 57.55 -34.49 0.0000 B3 *DT3 *S3 ~BEAM SW 100.00 -307.59 -4.71 7.95 -0.01 59.86 36.53 0.0000 B4 *DT4 *S4 ~BEAM SW 100.00 -307.59 -4.71 -7.95 0.01 -59.86 36.53 0.0000
+++ B E A M L O A D S T A N D A R D +++
===========================================
Units Are MPA, Degrees, Meters, and M-Tons Unless Specified
Forces For Most Severe Load Case with Axial Load Greater Than 0
% Dist Axial /------ Shear -----/ /---- Bending ----/ Pressure
Element /-- Node Names -/ Class Case From A Load Y Z Torque Y Z
-------- -------- -------- -------- -------- --------- --------- --------- --------- --------- --------- --------- ---------
B1 *DT1 *S1 ~BEAM SW 100.00 -306.51 4.71 -7.64 -0.00 -57.55 -34.49 0.0000
B2 *DT2 *S2 ~BEAM SW 100.00 -306.51 4.71 7.64 0.00 57.55 -34.49 0.0000
B3 *DT3 *S3 ~BEAM SW 100.00 -307.59 -4.71 7.95 -0.01 59.86 36.53 0.0000
B4 *DT4 *S4 ~BEAM SW 100.00 -307.59 -4.71 -7.95 0.01 -59.86 36.53 0.0000
I cannot explain the reason for such a large difference between the expected ground reaction and the obtained axial force at column's base.
Any hints?
Thanks in advance,
Doug
EDIT: SOLVED, THE PROBLEM WAS THE FACT THAT A NODAL WEIGHT WAS DEFINED AS A LOAD_GROUP (IT WAS SMEARED ACROSS MULTIPLE NODES). THE SOLUTION WAS JUST RESTRICT TO THE LOAD_GROUP TO SPECIFIED NODE
&DESCRIBE LOAD_GROUP ITEM *dt5#weight *dt5 766 15 20 18
THE ISSUE CAN BE CLOSED.
Great to read that you solved the problem.
Thank you for reporting back.
Georgina Maldonado
Dear Georgina,
a side question about LOAD GROUPs: in the manual there is a statment: "When a stress analysis is performed, the total load on the group will be distributed to the nodes associated with the points by a least squares technique.".
I'm asking if it is possible to obtain from moses how a specific load group is distributed on the affected nodes (in terms of nodal individual forces/moments)?
Thanks in advance
Hi Doug,
I received notification that you added to this thread. The notification had a question about reaction forces. That is not the question you are asking here. Let me know if a question has been lost.
For the question on the above, I am not clear on the exact report you are looking for. But there is the exp_aload command. That will export the applied loads. The generated file is meant as an input into other programs. I am saying this to point it out is not a formatted report with column headings.
You can also ask for the loads on beams (BEAM LOAD). You can restrict the load to the load group. You will first have to make a load case that only has that load.
I hope this helps.
georgina
Thanks Georgina,
yes, the exported file contains all needed info, and allows for debugging the model (and yes, the latter question was really linked to the thread subject, because the wrong results were due to erroneously smearing the weight load also on the restrained nodes).
Best regards
O.K. for now.
If you have further questions please post.