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simply supported beam
Posted Apr 5, 2013, 6:03 p.m. EDT Structural Mechanics Version 4.3 2 Replies
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Hi,
How do i define the constraints for a simply supported reinforced concrete beam which has both truss and solid mechanics elements.
Do I use boundary conditions or edge conditions
How do i define the constraints for a simply supported reinforced concrete beam which has both truss and solid mechanics elements.
Do I use boundary conditions or edge conditions
2 Replies Last Post Apr 25, 2013, 5:33 a.m. EDT
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Posted:
1 decade ago
Hi
knitting together trusss, beam, shell and solid (or some of them) is always delicate, as the truss, beam shell are all 1 or 2 DoF lower than Solid, so ideally a point (end of) a beam or truss shold be linked to a boundary = surface on the solid, for that one need to use projection mapping, and weak constrains. Also beam, truss and shell solve for displacements and angles, and Solid only for displacements, so one need to couple correctly the angles from the beam/truss (or shell) to the sold correctly. Else one obtain "mechanisms" or hindges and funny results
All this is possible, it's only that COMSOL does not have any handy scripts to do it for us, we need to apply it by hand link by link. This is rather common in many traditional FEM programmes, but with COMSOL you can play with the equation too, to make your own hinges and links
--
Good luck
Ivar
knitting together trusss, beam, shell and solid (or some of them) is always delicate, as the truss, beam shell are all 1 or 2 DoF lower than Solid, so ideally a point (end of) a beam or truss shold be linked to a boundary = surface on the solid, for that one need to use projection mapping, and weak constrains. Also beam, truss and shell solve for displacements and angles, and Solid only for displacements, so one need to couple correctly the angles from the beam/truss (or shell) to the sold correctly. Else one obtain "mechanisms" or hindges and funny results
All this is possible, it's only that COMSOL does not have any handy scripts to do it for us, we need to apply it by hand link by link. This is rather common in many traditional FEM programmes, but with COMSOL you can play with the equation too, to make your own hinges and links
--
Good luck
Ivar
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Posted:
1 decade ago
thank you