Model Rigid Element

Hi, I am a beginner of Ruaumoko, if I would like to create a rigid element between Node 1 and Node 2, how can I use the Rigid Link to model it? Do I need to create two more nodes? if yes, where to create the two more nodes? or I can create an elastic element with the very large Young Modulus? Thank you so much.

you can create two nodes more with the same coordinate of the node1 and node 2. If you want then the element is rigid then its elastic rigid has to be very large.

We have always tried to avoid pretending to have a rigid element. Slaving is one possibility. Putting in very stiff numbers (I know the mathematicians talk about penalty functions, but do not play with finite precision arithmetic) is very dangerous, if you put in a dummy member 10^6 stiffer than the other members in your structure you have lost about 6 significant digits precision in your analysis. You only have about 14 digits to start with and the loss may become quite significant. In the 1970s when most computation, by default, was about 6 to 7 significant digits, putting 10^3 different stiffnesses led to us having pushed on a structure come out to meet us in one case, i.e. total loss of precision. This is why we have the option of the use of the 4 node beam with rigid links (Infinite stiffness) to get the effects without any loss of precision. In general slave where possible.