Struts stronger in tension?

[Norcalplanner]

In all my time with KSP, I don't ever recall seeing anything about the strength of struts in tension vs. compression. Does the physics model go in to this level of detail, ot is the strength the same in both directions? It would seem intuitive that they should be stronger in tension.

Edited July 31, 2015 by Norcalplanner

[Laie]

It's counterintuitive, but once I noticed that struts can act as sticks or girders, I started to regularly use them as such and never noticed any difference. Which doesn't mean there is none, of course. But it's certainly not obvious; and knowing a thing or two about programming, I'm inclined to believe that it really doesn't matter if you push or pull.

[pincushionman]

I think they don't care about direction at all. Which implies they're just in strong in shear as well.

Which, as a structural engineer, twists my head around the wrong way every time I have to deal with it.

[GDJ]

They just add stiffness and increase the breaking limit of whatever part(s) they are attached to. I don't think KSP goes that deep into compression / elasticity / shear on those things.

The Firespitter biplane cables and the wood wing struts do exactly the same thing, just look different and have different mass.

[Claw]

Well, they don't exactly change the strengths of the part they are attached to in terms of that part's breaking force and totorque. They add joints for the physics engine to distribute forces to. So yes, the increase the overall strength, but they don't change the values for an individual part.

There are only two breaking forces specified. Breaking Force, and Breaking Torque. Based on the physics engine, I don't think there is a difference in tension vs. compression, but there is a torque value.

Cheers,

-Claw

[Norcalplanner]

Thanks for the info, everyone. I'll go ahead and mark it answered, but I think I'm going to do some experiments. I have an idea for a test rig that should answer this definitively.

[Sharpy]

If they merely reinforced joints, the effect of connecting ends of two long, parallel elements (think two long SRBs on a bicoupler) would be the same at the far end as right by their attachment point...

[Laie]

If they merely reinforced joints

As claw said, they don't: they create a second connection between two parts.

Often the strut is much more stable than the original joint, so it will be a great improvement no matter where you put it. But if you want to / have to get serious, location *does* matter.