On a horizontal piping, how to set a horizontal spring on it. For example, the horizontal piping's direction is +X, node 10 is the X direction restraint, then the displacement of node 20,30,40 after the node 10 is positive X, how can I set a horizontal spring on node 30 which can also to act a positive X direction force to the piping?

hi guang,
u cant set a spring of horizontal direction for a horizontal pipe. u can only put a spring either vertical upward or downward direction in ceasar.

Apparently you wish to preload a horizontal spring. CAESAR II has that feature only for vertical supports - hangers.

What you can do is add the restraint at 30 in the X direction and enter the stiffness for this spring. Also add a CNode for this spring and then specify an X displacement for that CNode where displacement equals (preload/stiffness).

Of course, make sure the results reflect what you wish to model.

Thanks for the response of raju soni and Dave Diehl.
But What I want to do is not to preload a horizontal spring. For my model, the displacement of node 30 is positive X, so the force of node 30 is negative X.What I want to do is to set a positive X force to the pipe, also I don't want to preload the horizontal spring, I only want it can set a positive load on the operation case not in the sustain case, the load on the sustain case is zero. So if I add the restraint at 30 in the X direction and enter the stiffness for this spring, I will find the force on node 30 is negative X. How can I do?

Spring for horizontal(lateral) direction ? Are you trying to do research work for stress software ? or Is it real piping engineering work ?

It's make sense if you want to consider the effects of flexibility from sway brace or structural attachment. But spring....for what ?

It seems that the solution is to provide more flexibility to X direction, i.e put more elbows or change nozzle orientation. The horizontal force by spring is not proper practice. It's merely the number from Caesar II.