Analysis Error in ETABS-Global Force Balance Relative Errors

[SteelStructureDesign]

Hello all,

When I want to run analysis after modelling and loadind etc., it is running and complete without any problem. But when I want to see detailed them command File\Last Analysis Run Log I can see folloving information in the middle of the long lists.

So what does it mean? Is there any important mistake? What should I do? Can I ignore it?

G L O B A L F O R C E B A L A N C E R E L A T I V E E R R O R S

PERCENT FORCE AND MOMENT ERROR AT THE ORIGIN, IN GLOBAL COORDINATES

LOAD FX FY FZ MX MY MZ
OLU 1.55E-11 1.93E-10 3.44E-11 1.78E-10 1.58E-11 1.75E-10
KAR 5.31E-11 1.44E-10 2.90E-11 1.35E-10 1.96E-11 1.58E-10
DEPXBOD1 3.10E-10 2.91E-10 7.44E-13 3.26E-10 3.49E-10 7.29E-12
DEPYBOD1 5.83E-11 1.74E-09 3.93E-13 1.60E-09 5.39E-11 1.58E-09
RUZGARX 2.78E-08 1.59E-09 1.14E-10 1.65E-09 3.12E-08 2.40E-08
RUZGARY 4.12E-10 2.15E-07 2.93E-11 1.98E-07 3.49E-10 2.04E-07
HAREKETL 2.21E-11 2.02E-10 1.76E-11 1.76E-10 3.51E-12 1.87E-10
TOPRAKYU .000000 .000000 .000000 .000000 .000000 .000000
DEPXUST1 3.99E-08 1.40E-09 1.86E-10 1.36E-09 4.48E-08 3.76E-08
DEPYUST1 1.05E-10 3.02E-07 3.52E-11 2.77E-07 1.32E-10 2.88E-07
DEPXBOD2 2.78E-10 8.40E-11 6.43E-13 9.36E-11 3.12E-10 1.80E-10
DEPYBOD2 7.32E-11 1.84E-09 3.51E-13 1.69E-09 6.76E-11 1.65E-09
DEPXUST2 3.75E-08 2.39E-09 1.61E-10 2.50E-09 4.21E-08 3.00E-08
DEPYUST2 1.05E-09 3.01E-07 4.73E-11 2.77E-07 9.20E-10 2.85E-07
TRIBUTAR 3.67E-11 1.78E-10 2.97E-11 1.63E-10 5.53E-12 1.77E-10

MODE FX FY FZ MX MY MZ
1 0.000218 0.000251 0.000324 0.000101 4.98E-05 7.34E-05
2 1.37E-06 1.38E-05 7.16E-05 4.20E-05 7.15E-05 2.98E-06
3 5.23E-05 3.89E-05 5.43E-05 3.44E-05 0.000125 1.39E-05
4 0.000967 0.000411 0.000474 0.000281 0.000627 0.000150
5 0.015377 0.043125 0.017567 0.015376 0.006402 0.020985
6 0.002910 0.003262 0.018420 0.009948 0.012042 0.002802
7 0.000904 0.001973 0.001712 8.27E-05 0.002194 0.002057
8 0.001424 0.002588 0.007620 0.004768 0.004964 0.002102
9 3.75E-05 0.000113 9.04E-05 0.000109 4.96E-05 0.000106
10 4.80E-05 3.65E-05 2.14E-05 2.86E-05 4.10E-05 7.23E-05
11 0.000473 9.31E-05 0.002751 0.002148 0.002917 0.001403
12 0.000423 5.62E-05 0.002270 0.001298 0.001741 0.000880

 

[slickdeals]

Basically it checks equilibrium of the structure. If values that are reported are close to zero, then you can be certain that all the input loads match the external reactions. Meaning [Σ]F=0 and [Σ]M=0

 

[SteelStructureDesign]

Hello again,

Thank you very much for your quick replay.

So, If I dont misunderstand you I think all of my total F and total M values very very close to zero and there is no problem about this warning at all. Am I right?

Latif

 

[slickdeals]

I would still check the warnings and see if they can be ignored. Sometimes the warnings are generated by meshing that creates a stiff element adjacent to a not-so-stiff element. Sometimes these warnings can be generated when you accidentally have two points that are very close to one another and the auto-merge tolerance is set to a very low value.

The only warnings you have to be careful are the ones that are created prior to analysis (in the .wrn file). They are meshing warnings that can cause inaccurate load transfers and must be fixed.