elastomeric bearing modelling

fabbrob1 · Post by **fabbrob1** » Mon Oct 19, 2009 6:28 am

hi,

i am studying a bridge before and after retrofitting and i need to model the elastomeric bearing.

for the original model,i put a MPconstraint (rigid link constraint: beam) between the upper node of the column and the node of the deck (which is not the same)

now i have to simulate the elastomeric bearing, in longitudinal and transversal direction. A bi-linear spring.

i have not two nodes at the same point to use the zero lenght element.

So, how can i model it?

Truss element? does it work also without flexural resistance? (the bearing works only in longitudinal and transversal directions)

And for the material? Hysteretic?

Thank you very much

silvia · Post by **silvia** » Mon Oct 19, 2009 6:42 am

zero-length element. the hysteretic material is good, but how are you going to model the damping?

fabbrob1 · Post by **fabbrob1** » Mon Oct 19, 2009 7:19 am

the beams of the deck are connected with a zerolenght element above the column, between them, and also to the trasversal beam. But between this node and the upper node of the column i put the rigid link constraint with a free space to simulate the distance due to the trasversal beam.

so i cannot use the zerolenght element to substitute this link.

do you think it is better if i change the model?

silvia · Post by **silvia** » Mon Oct 19, 2009 10:03 am

it's up to you.
remember, you can use rigid offsets, specified in the transformation command, and equalDOF commands.