What is Vector1, Vector2... in the Displacement input?

What does the Vector1, Vector2, ... Vector 9 represent in the Displacement input screen?

You can specify the displacement of a given node on a given element up to 9 different ways. Then you specify when those displacements apply in the load case editor as D1, D2... D9.

Same applies to point loads, F1... F9 and distributed loads, U1... U9.

To add onto the answer above, these are external displacements your piping is seeing in the directions you defined in the vector.

I understand displacements but why call it Vector 1, Vector2 etc.

Is there some significance that I am missing as to why it is called that??

CAESAR II is just allowing you to define up to 9 sets (vectors) of displacements.

Let's say your line is tied to a much larger header having multiple operating modes. Say case 1, the header goes +1" in the X direction. Case 2 it goes to -1" X and +1" Z. You can define D1 = {1,0,0,0,0,0}*, D2 = {-1,0,1,0,0,0}*. D1 is displacement vector 1, D2 = displacement vector 2 etc.

In your load case setup, you can even combine them too if you want.



*{DX, DY, DZ, RX, RY, RZ}

also, displacement is a vector since you have magnitude and direction. just like the force input.

An additional note. You might be tempted to say D1 = {1,0,0,0,0,0} and D2 = {0,0,1,0,0,0} thus D1+D2 = {1,0,1,0,0,0} but this would be incorrect.

I think CAESAR averages the 2? D1+D2 = {0.5, 0, 0.5, 0, 0, 0}.

(Or it could also do SRSS - I just don't remember.)

So Vector1 corresponds with T1, Vector2 corresponds with T2 and so on. Is that correct?

Tom45,

The terminology associated with matrix solutions (i.e. [K]{x}={f}) typically refers to the stiffness matrix [K], the load vector {f}, and the displacement vector {x}.

When you have multiple load cases, you have multiple load vectors, i.e. {f1, f2, f3, ...}, which correspond to multiple displacement vectors i.e. {x1, x2, x3, ...}. Now, what you put in each load vector is up to you. However, to keep ones sanity most people would put T1, P1, D1, F1, U1 and so forth in "f1". Then T2, P2 and so forth in "f2", and so on. Of course this idea falls apart in more complex systems, especially when occasional loads are considered.

c2 doesn't care, the software does not force any particular convention. There is no rule that says T1 must go along with P1 - that is determined by your system. This is why it is a good idea to use the "load case name" option.

When automatically specifying load cases, CAESAR will often assume correlation between P1, T1, etc. However, that's just a point of convenience if you set it up that way.

Thank you Richard, makes perfect sense now.