Incompatible load combinations

[3JC]

Dear collages from forum,

I have a question: is it possible to define the uncompatibility of two load, previous to the automatic generation of load combinations by the software? I'm calculating a 2d portal frame, and due to the asimmetry, I have to consider two different wind load directions and also two different load crane possitions. Thank you very much.

Regards,

Juan José

 

[johnbridge231]

What you mean my "uncompatibility of two load"??

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[3JC]

Dear John,

Thank you very much for your response. I think I have a mistake in the title: what I want to say is if is it possible to define that two (or more) loads are uncompatible in the sense that they can't be together in the same combination. For example: wind in both direcctions can't appear as a combination.

Regards,

Juan José

 

[johnbridge231]

Dear 3JC,

Of course you can do that. First define the load cases, which can be independent, for example wind in a direction, snow, other live loads etc.
This can be done from Define->Load patterns

Then, you can create one or more combinations. In each combination, only the load patterns that are contributing to it will appear.


Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[dgerashki]

I'm pretty sure, that when you use SAP2000 for automatic combinations, it doesn't combine loads of one type (for example different WIND loads defined in Load Patterns).

In fact I don't use this function at all, because in v.14 it doesn't combine SNOW loads acc. to Eurocode.

 

[3JC]

Ok, thank you very much. But isn't there any option where you can say to the software not to combine some actions in combinations?

Regards,

Juan José

 

[johnbridge231]

3JC, dgerashki is right, the best is to manually define the load combinations. Furtmore SAP2000, uses some default load case factors that the user cannot change (for example the live load contribution to seismic mass is always taken as 0.3, which is not always so).

Regards.

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html