Arrangement for Worst load case

[stroxy]

If I have a tank divided into say 5 compartments and I want to analyze the tank for different combinations of "full tank" and "empty tank" do I have to define a separate load case for each tank or does RSA do that automatically.  This is analogous to say loading a beam on alternate spans as well as all spans in order to generate  max internal forces, reactions etc.

[Rafal.Gaweda · Accepted solution]

Define loads in tanks as separate laocdcases then program may combine them automatically

[Rafal.Gaweda]

Example movie: http://screencast.com/t/IJLpfCBMx

[stroxy]

I noticed you had "AND" as the operator for live loads in the "Relations" Tab.  Thought it would be "or(incl)" as in "Groups" tab

[Rafal.Gaweda]

IN case of one group in Nature it does not matter.

This is the operator between "groups"

Or-incl operator within the group

Example movie how to deal with groups and operators : http://screencast.com/t/RA4Nnv5XwBq

[stroxy]

Thanks, I get the drift .... love these screeen casts 

[HoshangMustafa]

Hi Rafal

You used this for bars. Can this be used for panels (floors)?

I tried it for panels. It gave many many combination (over 64000). Of course after calculation (i.e., meshing)

What is the wrong?

If so, how can it used for panels (floors)?

[Artur.Kosakowski]

The operators among groups of loads are model type independent.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[HoshangMustafa]

Hi Artur

Thank you.

I wrote in my post:

I tried it for panels. It gave many many combination (over 64000). Of course after calculation (i.e., meshing)

What is the wrong?

If so, how can it used for panels (floors)?

So, 

1- What, and

2-Why

Can I attach my model and you apply the code combination and see the number of combinations?

[Artur.Kosakowski]

The number of combinations is the function of number of load cases and the relations you defined among them. The operators discussed in this topic influence this number e.g. fol live loads Q1, Q2 and Q3 you will have

1 combination for AND (Q1 + Q2 + Q3)

3 combinations for OR (EXCL) ( Q1 ; Q2; Q3)

7 combinations for OR (INCL)  (Q1 ; Q2; Q3; Q1 + Q2; Q1 + Q3; Q2 + Q3; Q1 + Q2 + Q3) 

The way to reduce the total number of combination is to group live load cases trying to exclude these that you know do not create the worst conditions). The simplified code combinations where you can set such criteria are currently available for bar and nodes only.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[HoshangMustafa]

Hi Artur

The way to reduce the total number of combination is to group live load cases trying to exclude these that you know do not create the worst conditions

I have 2 dead load cases with 17 live load cases (17 panels each panel with its live load). I want to make worst combinations for

1-Columns

2- Beams (adjacent live loading for max negative moment, alternate live loading for max positive moment)

 I tried many many times but I couldn't manage it. The restriction which I encountered is that when selecting live load cases (e.g., 3 live load cases) for (Create a group from cases), these selected live load cases wouldn't be available for the next groups. Why?

Shouldn't it be available so that one easily can make groups of whatever live load cases the user may wish?

If you explain with a screencast.

[Artur.Kosakowski]

In such case you may try to use the simplified code combinations instead:

http://help.autodesk.com/view/RSAPRO/2015/ENU/?guid=GUID-043979B9-6EA9-4315-9511-AD6D01EFAE26

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.