Spring element

[Qingen]

Hi Steve,

I would like to use springs to connect the nodes of one component to one node of another component. Does PreView and FEBIO support this operation? I have read the manuals, but did not find anything about springs. If I can define spring elements in PreView, how should I do it? Or, before I import my model to PreView, I have to define spring elements in other software, such as ABAQUS?

Thanks a lot,

Qingen

[orsialex]

I am also having trouble figuring out how to create springs within the preview software. I have been trying to follow the directions on the forum in other posts.

So far I have been able to select a node by using the mesh selection -->Node selection

However, I am unsure how to relate this function to telling the spring create function to use this node I selected. Is there a way to do this?

I have been able to create springs through the input file, however, I would like to be able to do this using PreView, as it would cut down my work load considerably!

Thanks

-Alex

[maas]

Hi Qingen and Alex,

Yes, you can create springs in PreView, although the process is somewhat cumbersome. The problem is that springs can only be connected to nodes of the geometry (not of the FE mesh). After you import your geometry into PreView, you need to identify which FE nodes you want to connect with springs. You can select them in the Mesh panel. After you select the nodes, click the "partition" button to turn those FE nodes into geometry nodes. After that you can select springs on the create toolbar (or create panel if you are not using PreView 1.6 or up). Make sure you are in node selection mode (the node selection button on the main toolbar, not on the Mesh panel). Activate the Pick button and select the two nodes. That should do it. As said, the process is a bit cumbersome but hopefully will become easier in the near future. Let me know if you have any problems with this.

Cheers,

Steve.

[Qingen]

Hi Qingen and Alex,

Yes, you can create springs in PreView, although the process is somewhat cumbersome. The problem is that springs can only be connected to nodes of the geometry (not of the FE mesh). After you import your geometry into PreView, you need to identify which FE nodes you want to connect with springs. You can select them in the Mesh panel. After you select the nodes, click the "partition" button to turn those FE nodes into geometry nodes. After that you can select springs on the create toolbar (or create panel if you are not using PreView 1.6 or up). Make sure you are in node selection mode (the node selection button on the main toolbar, not on the Mesh panel). Activate the Pick button and select the two nodes. That should do it. As said, the process is a bit cumbersome but hopefully will become easier in the near future. Let me know if you have any problems with this.

Cheers,

Steve.

Thanks a lot, Steve. I have also noticed that in the latest version of Preview, there is an icon of spring on the Create panel. I will try what you mentioned above. In case I have problems, I will come back to you if you do not mind.

Cheers,

Qingen

[orsialex]

Hi Steve,

Thanks for the info, I am able to partition the nodes. However, I then go into the node selection mode on the main toolbar. I can see the nodes which I have partitioned, which is good. However, when I select the pick button, I am unable to select anything. I can select the nodes if I do not have the pick button selected, but nothing happens after this. Is there a step I am missing here?

Thanks for the help!

-Alex

[maas]

Hi Alex,

I just tried it myself (with version 1.6.2) and it seems to be working fine. After you click the Pick button, it should be highlighted in yellow. You can then select the nodes (assuming you have the node-selection button selection on the main toolbar). When you click a node, the node number shows up in either N1 (for the first node) and N2 for the second node. After that, click the "Create" button to create the spring. Hope this helps.

Cheers,

Steve.

[Qingen]

Hi Qingen and Alex,

Yes, you can create springs in PreView, although the process is somewhat cumbersome. The problem is that springs can only be connected to nodes of the geometry (not of the FE mesh). After you import your geometry into PreView, you need to identify which FE nodes you want to connect with springs. You can select them in the Mesh panel. After you select the nodes, click the "partition" button to turn those FE nodes into geometry nodes. After that you can select springs on the create toolbar (or create panel if you are not using PreView 1.6 or up). Make sure you are in node selection mode (the node selection button on the main toolbar, not on the Mesh panel). Activate the Pick button and select the two nodes. That should do it. As said, the process is a bit cumbersome but hopefully will become easier in the near future. Let me know if you have any problems with this.

Cheers,

Steve.

Hi Steve,

If I have a group of nodes, all these nodes connect to another one node (say, Node B) to firm a lot of springs. Instead of clicking each node of the group and Node B a few times, is that possible to choose all the nodes of that group and Node B only once to create all the springs?

Best,

Qingen

[maas]

Unfortunately not. You'll have to create the springs one by one.

Cheers,

Steve.

[Qingen]

Unfortunately not. You'll have to create the springs one by one.

Cheers,

Steve.

Many thanks for your quick resply and clarification, Steve.

Cheers,

Qingen

[Qingen]

Hi Alex,

I just tried it myself (with version 1.6.2) and it seems to be working fine. After you click the Pick button, it should be highlighted in yellow. You can then select the nodes (assuming you have the node-selection button selection on the main toolbar). When you click a node, the node number shows up in either N1 (for the first node) and N2 for the second node. After that, click the "Create" button to create the spring. Hope this helps.

Cheers,

Steve.

Hi Steve,

I have tried the procedure that you described. I am able to create springs successfully. However, when I exported the .feb file, Preview crashed. I have also noticed that you mentioned in another post (http://mrlforums.sci.utah.edu/forums...ghlight=spring) that a boundary condition (or a contact interface) needs to be defined before the .feb file is exported. And I have followed this rule as well. However, it still does not work (Preview crashed as well). Maybe I missed something else? I attached a simple test model (I have also tried on a complex model, and the same porblem occured). Could you have a look at it please?

cheers,

Qingen