Loading combination generator - unreliable when more than 1 live load case?

[mathias_peron]

Hi everybody,

It seems that when I have more than 1 live load case, the loading combination generator has trouble giving me all relevant combinations to the Eurocode. See below my example.

Case 1:

Load cases:

1 - DL

2 - LL (cat. E) - phi0 = 1.0

3 - LL (cat. H) - phi0 = 0.0

4 - Wind - phi0 = 0.6

5 - Snow - 0.7

I should have 3 types of design combinations : dominant live / dominant wind / dominant snow

But as you can see below, only the dominant live combination is proposed by the generator.

Case 2:

I have tried this again with only 1 live load case, and it seems to work. See below.

Load cases:

1 - DL

2 - LL (cat. E) - phi0 = 1.0

3 - Wind - phi0 = 0.6

4 - Snow - 0.7

This time I have the 3 types of design combinations : dominant live / dominant wind / dominant snow

It is possible that I made a mistake with the generator parameters, but I don't think so. Could someone confirm please?

PS: please find Robot files attached.

Regards,

Mathias.

[Simau]

@mathias_peron 

When you generate the combinations try this, and look if you get what you expect

[mathias_peron]

Hi Simau,

Thanks for your answer but it doesn't work. Any other idea?

Regards,

Mathias.

[Simau]

Hi @mathias_peron 

In your first message you hilighted some combinations as dominante live (wind, snow).
Why do you think that these comb are dominante.
When you made a code verification, each bar or panel have its dominante combination, in an other word each comb may be dominante for a particlar element and not for another.

[mathias_peron]

Simau,

According to Eurocode 0, when there are more than one variable load we should use φ0 factors to determine different loading combinations with MAIN and ACCOMPANYING variable actions. See table below:

So if I have, lets say:

Load case 1 - Dead load

Load case 2 - Variable load 1

Load case 3 - Variable load 2

I should have loading combinations with Variable load 1 dominant (Variable load 1 MAIN and Variable load 2 ACCOMPANYING) and vice versa.

Has anyone else trouble with this?

@Artur.Kosakowski ?

Regards,

Mathias.

[Simau]

@mathias_peron 

You have set LL2 as Category H. Change it to cat A for example

[mustafahesenow]

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