Connection of truss for pin and roller support?

[thomaschua17]

I understand that when modelling a truss system, you should assign one end as pinned and the other as roller. This has been bothering me for quite some time now as I was told at work that just detail both the supports of the truss as an anchor bolt with base plate connection.

If I do this, won't the connection of the truss be pinned at both sides? Is there a proper way of connecting a truss to a concrete beam as a roller support?

Say the truss is a simple fink truss.

Thank you!

 

[Lomarandil]

What supports the truss?

If the supports are flexible in the truss longitudinal direction (e.g. dimensional timber or light gage steel wall perpendicular to the truss), then a pin and roller is a good assumption regardless of the connection. While the connection may restrict movement, the wall(s) will move.

If the supports are massive and rigid, then it's possible to develop a pin-pin condition (which will affect the truss). Although it's also possible to detail a slotted bolt or sliding bearing pad connection that would ensure linear freedom.

It's all dependent on the relative stiffness. Run your truss model once with pin-roller to see how much it wants to move to inform your decision.


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just call me Lo.