Beam end deformation are very strange
I have modeled a deck with composed beams. When I want to see the deformed shape from
moving load LM1 the value is incorrect and the end beams deformation is very strange.Answer:
Moving load results are the envelope of results obtained.
For example, 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 hang 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.
BEAMS END DEFORMATIONS.jpg
TAB 50 M PREC.mcb