Hi,
I am trying to do a 3 point bend test for a lattice structure. The beam is already latticed and is a nodal structure. The pins are discrete rigid shells.
3 interactions were created where the surface of the pins were made Master and the slave being a nodal set consisting of just the top most nodes of the latticed beam. This can be seen in the image. The friction defined is 0.2.
The simulation runs but in the animation, the beam flies out instead of bending. I have attached the video file here.
Any advice on improving this would be very helpful. Is there something missing in the interactions or the way I am defining it?
Thank you for your inputs!
Hi. If I understand correctly, the top pin must move downward, but it is motionless. Let its RP moves in z-direction due to prescribed load or displacement. Moreover, the central node of the beam must be constrained from moving in x- and y-directions.
As far as I know, if the nodal point from circular block touches (share the same node) the beam, you don't need to define any specific contact, rather load will be transferred from node to node.
I would add, it is necessary to restrict movements in Z directions for beam at contact lines with both cylindrical supports. Beam is free to move in Y direction and free to rotate at those contact lines.
Victor J. Аdlucky
I have already defined it as such. Attached is the boundary conditions that i have specified. And the job still gets aborted halfway without any sign of the pin going downwards.
Central node of the beam meaning, only the centre portion of the nodes that will be contacting the cylinder?
Thanks.
Alberto Naranjo
By restricting movements in Z, do you mean only extracting the nodes within the zone that will be contacted at the support pins and placing a z-restriction?
While the rest of the beam can be left as it is?
Thanks
Everywhere your beam should be free to rotate, in all zones in contact with rolls. You need only one restriction in X direction for example at central roll. These conditions are for every nodes in contact with rolls. Do you let rotate the rolls during deformation? It is important.
As central node of the beam I meant node at the intersection of 3 planes of symmetry. It will not come to contact with cylinder. Due to symmetry it must have the next BC: U1=U2=UR1=UR2=UR3=0. The red circle is its projection on yz plane (1.png) and xz plane (2.png).
All nodes are contacted with central roll.you need one restriction in centre.whenever rotate it gets deform.
Hi Jerin Wesley R
I have attached a figure with some interaction properties which should work.
With regards to the rolling of the lattice off the pins, since the lattice is 'ideally' symmetrical, you can model a half, or even quarter model. Same stresses and strains are expected from the ideally symmetrical lattice anyway.
Hope it work.
Regards,
Wee
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