2D Truss analysis problem

[Anonymous]

I started modeling a steel 2d truss as shown in the first picture and the results were true and actuate

but when I add columns under the truss as shown in the second picture the analysis changed 

Knowing that I am using 2d truss type of structure also I tried to use 2d frame it also has the same problem

 

all the members are (simple bar)

I'm sure that there is a solution for this problem 

Waiting for comments 😄

[Artur.Kosakowski]

Hi @Anonymous

As far as I can see you just transferred the supports from the truss model to the bottom of the columns whereas you should keep the same boundary conditions at the columns' tops (as releases) instead.

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[Anonymous]

You mean that I should keep the supports in the original location ???

[Artur.Kosakowski]

Hi @Anonymous

No, what I meant was that you should define releases which correspond to the original supports at the top of the columns in your second model as by default the connections among the columns and the truss are fully fixed.

If one or more of these posts answered your question, please click Accept as Solution on the posts that helped you so others in the community can find them easily.

[Muhammed.OPERA]

Hi @Artur.Kosakowski

I think the results will change even if you have made a releases to the top of the columns.

[Artur.Kosakowski]

HI @Muhammed.OPERA

Why not to run a quick test? 

 

If I managed to answer your question(s) press the Accept as Solution button please. This will help other users to find solution(s) much faster. Thank you.

[Anonymous]

Could You show me the Fx Digram ?

[Artur.Kosakowski]

HI @Anonymous

It is actually displayed on the picture I attached 

[Anonymous · Accepted solution]

 i see that but i want to see the values of the forces in members 

i try to solve this problem by make robot understanding that the hole members of structures are tension/compression members by :

Geometry ==> Additional Attributes ==> Advanced Bar Properties 

then select all the members and press  ok but the values of reactions still different

[Artur.Kosakowski · Accepted solution]

HI @Anonymous

You can't do this for chords.

  

If one or more of these posts answered your question, please click Accept as Solution on the posts that helped you so others in the community can find them easily.

[Anonymous]

you mean that the method i apply is correct but i should select specify members except the cords??

[Artur.Kosakowski]

Hi @Anonymous

Cords and columns 

If one or more of these posts answered your question, please click Accept as Solution on the posts that helped you so others in the community can find them easily.

[Anonymous · Accepted solution]

Thank you guys for the help

The problem solved

summary for the solution :

1-Use 2D frame type of structure 

2-Use tension/compression members by :

Geometry ==> Additional Attributes ==> Advanced Bar Properties 

3-Release for the column.

Finally Thanks 😄