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Riks vs General analysis 1

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SofiaB

Civil/Environmental
Joined
Jul 9, 2020
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27
Location
PT
Hello everyone!

I am analyzing an SHS steel truss, simply supported, with concentrated forces (in Newtons) applied in the top nodes. The loads are applied in reference points that are constrained, type coupling, to the section of the chord. All the top nodes have a boundary condition to prevent out-of-plane displacements. I'm using a general static analysis and a nonlinear material.

Since what I want to achieve is the force-displacement curve of each of the truss nodes to analyze the joint's behavior, it's important to study them above the yield limit. The problem was after increasing the load from 84 N to 200 N the vertical displacement(U2), as well as TF2, were the same! Is this occurring because of the type of analysis I used? Should I switch to a Riks method?

I will leave some pictures for a better understatement.
Thanks in advance.

0_l2onl2.png

Captureimag4_nvvjkk.png
Captureimag5_ahybgh.png

7_wrypif.png

3_aqfsib.png
 
Riks step might be a better choice, it's great for postbuckling simulations. But you can also try the dynamic (quasi-static) step. Also, keep in mind that plastic material data is held constant outside the range of specified values.
 
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