Model Using Mass21 Question 1

[Stringmaker]

I am modeling a circuit board using shell elements in Ansys. So far I have been creating the model in Ansys by making the base area and subtracting out circles in locations where wires solder into the board. To model the wires using mass21 elements meshed at the keypoints created by the holes has been a convenient approach thus far. However, I have some surface mount components now which naturally there are no holes in the board for. So somehow I need to add mass21's where there are no keypoints now. How would a person go about doing this? I searched in the Ansys help quite extensively and wasn't able to find anything on this. If I create an individual keypoint that is not a child of the area which I'm meshing will the two automatically be lumped together? Do I need to perform some operation to make a keypoint a constituent of an area? Or is there some other way that I can add a mass21 element to an area without a keypoint being there? Any help on this matter would be very much appreciated.

Thank you!
-Brian

 

[Drej]

>If I create an individual keypoint that is not a child of the area which I'm meshing will the two automatically be lumped together?

No. You can add a keypoint (K) and then mesh this (KMESH) or you can just create a node (N) and then mesh this (E or EN), but you'll obviously need to connect this element back to the board. To do this you'll need to create a "spider" of line elements back to the board as follows:


* <--- mass21
/ \
/ \ <--- "spider" of beam elements with rigid properties (or use MPC184 element)
/ \
----------- <--- CB


Hope this answers your question.


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[Stringmaker]

Thanks Drej! This works like a dreams. I've been very pleased with the results thus far.

-Brian