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BEAMS END DEFORMATIONS

Question:

                  Hello,
  
I have modelled a  deck with composed beams. When I want to see de deformed shape from
moving load LM1 (please see the attached capture) the value is incorrect and the end beams are
deformed very strange. Please tell me if I have made something wrong.

Thank you very much.

Best regards,


Answer:


Hello,
Greetings.

Thanks for reaching us.
Moving load results are the envelope of results obtained.
For eg. I view the displacement results for MVmin:LM1CAR, then results obtained will the minimum displacements (considering signs) for all the nodes. So, it will be independent of other nodes. The minimum node displacement for node 1 and node 2 may or may not occur for same vehicle load position. Hence, the displacement results are independent of each other.
When vehicle is placed on girder in between 2 supports, then the deformation for the girder is downward for that moving load.
Hence, critical deformation of each girder node will be obtained in MV min: LM1CAR. (Note: sign of the results) .
The end beams hangs just like cantilever. So, when the moving load runs over bridge, it will lift up and displacement is positive, thus result for critical deformation is obtained in MV max: LM1 CAR. 


Thus, the deformed shape obtained in MVmax or MVmin case is actually an envelope and is not true shape.

Creation date: 6/4/2021 3:30 PM (jatin2010)      Updated: 6/4/2021 3:30 PM ()
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BEAMS END DEFORMATIONS.jpg
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DataImage63.png
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TAB 50 M PREC.mcb
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