why can rockets bend?

[jastrone]

Why are rockets so soft? Why should struts even be needed? Rockets should not bend. Why do they wobble ksp?  its unrealistic. cant they at least make a setting to turn it off? Who had the idea to make wobbly rockets when creating a game?

Just why?

[paul_c]

I thought it was fairly realistic based on the forces exerted on the structure. Basically a too-powerful rocket can cause narrower components above to flex. In the real world, things would break/fail much sooner so you'd not see the extreme bending possible in KSP. Its fairly easy to stick a strut or two on, and they are "infinitely" strong, so what's the issue?

[KingDominoIII]

Believe it or not, metals are malleable- they bend. SN1, made of stainless steel, which is more resistant to force than aluminum, the metal most rockets are made of, imploded, and bent inward instead of shattering.

Airframes bend. It's a fact of aerospace. Look out the window the next time you're on a plane- you'll see the wings shaking as soon as you hit turbulence, and maybe before then. 

[The Aziz]

Because these rockets are made of many parts that are connected to each other by literally a single structural point - a node, not by many strong welds or whatever. So the physics make them bend. Single part, like a long tank or anything else, won't bend.

[vv3k70r]

1 hour ago, jastrone said:

Why are rockets so soft?

Because they are lightweight, kept in shape by preasure and struts. When they are empty they are in much lower pressure.

1 hour ago, jastrone said:

Why should struts even be needed?

Otherwise You can use thicker material and it bring some weight.

1 hour ago, jastrone said:

Rockets should not bend.

They do, ther are more like baloons. If You empty them and cut suports (struts are part of it) they just colapse.

Be happy that games phy do not consider TWR around 12 as a reason to crack the tanks after ignition. And most controls just to colapse.

1 hour ago, jastrone said:

Why do they wobble ksp?

Because they are unbalanced.

1 hour ago, jastrone said:

Who had the idea to make wobbly rockets when creating a game?

You designed rocket - You are only to blame for wobling. You make more - You learn.

1 hour ago, KingDominoIII said:

Airframes bend. It's a fact of aerospace. Look out the window the next time you're on a plane- you'll see the wings shaking as soon as you hit turbulence, and maybe before then. 

Aeroplane is hang in the air by the wing. They are quite flexible if compare to let say... bridges?

 

[Corona688]

3 hours ago, jastrone said:

Why are rockets so soft? Why should struts even be needed? Rockets should not bend. Why do they wobble ksp?  its unrealistic.

The game tolerates you building and flying them unrealistically when real ones would just blow up.  The joints have been strengthened over, and over, and over, well past the point of absurdity.

Perhaps if you include a screenshot we can make suggestions to improve it.

3 hours ago, jastrone said:

cant they at least make a setting to turn it off?

They did.  It's called autostrut.  Enable it in advanced tweakables.  It occasionally has unexpected side-effects.  Do not use autostrut if you plan to operate a motor vehicle in the next 24 hours.  Consult your physician.

 

[foamyesque]

Yeah, about the only structural failure you can reliably get any more is ripping wings off when executing 40g manouvers in the atmosphere. Nobody used to modern KSP has any idea what Wobbly Rockets(TM) used to be like. I bent some rockets into a clean horseshoe in days gone by.

[Vanamonde]

Real rockets are a lattice of load-bearing struts to withstand the forces acting on the vessel, covered by a smooth skin for aerodynamic reasons. There is considerable disagreement among KSP players as to how much of that structural support should be placed by the player and how much should be an inherent aspect of the parts. There's no final answer because it's a matter of player taste. I myself would find the game boring if I could just slap any old thing together and fly it without risk of failure, so I have no problem with adding some struts and stuff to keep my rockets from flexing or deviating. 

[Bej Kerman]

On 12/9/2020 at 7:20 PM, jastrone said:

Rockets should not bend.

This entire thread says no.

[Xavven]

  

22 hours ago, foamyesque said:

Yeah, about the only structural failure you can reliably get any more is ripping wings off when executing 40g manouvers in the atmosphere. Nobody used to modern KSP has any idea what Wobbly Rockets(TM) used to be like. I bent some rockets into a clean horseshoe in days gone by.

I totally remember those days! I joined KSP right around the time it entered Early Access on Steam, like 0.23 or something. Bigger rockets were so wobbly you'd have to build a skeletal structure out of i-beams and then attach the tanks to it. Bigger monstrosities would have dozens of struts. Most players on the forums recommended the Kerbal Joint Reinforcement mod which fixed the noodly-rocket syndrome.

Since then, the devs made the joints more rigid in stock, but if I'm not mistaken, the Kerbal Joint Reinforcement mod still exists for players who want even more rigid rockets. Just a suggestion for the OP. But personally, I think stock strikes a good balance. Rockets that are a reasonable size and don't have tanks hanging off the sides tend to be rigid enough, and a couple strategically placed struts here and there shores up wobbly issues on bigger rockets. But it's nothing like the old days where it looked like your rocket had a freaking spider web of struts all over the exterior.

[vv3k70r]

10 hours ago, Xavven said:

But it's nothing like the old days where it looked like your rocket had a freaking spider web of struts all over the exterior.

Most lightweight constructions looks that way before they get covered. We have many solutions how to hide them in real life, but they all are there for suport.

[YNM]

It really depends on your design. Struts can make short work to stabilize most things, although they can sometimes be not quite realistic either. Most softness I've seen in 1.10.0 / 1.10.1 is if you have those fairing-ed interstages, where you need to spam some struts, but it makes sense strength-wise (though placement-wise it's not quite sensible). I think most of the unrealistic-ness of rocket deflection in the game is partly because the deflections can only happen about one defined connecting point, whereas IRL it will happen throughout the whole length of the rocket.

Edited December 11, 2020 by YNM

[foamyesque]

On 12/9/2020 at 2:11 PM, vv3k70r said:

Aeroplane is hang in the air by the wing. They are quite flexible if compare to let say... bridges?

 

Depends on the bridge...

 

 

[vv3k70r]

3 hours ago, foamyesque said:

Depends on the bridge...

Decent bridge should be build of stone or wood like Romans did. It works - do not fix it. As You see improvments create issues - do not improve! I like my cave!

[Bej Kerman]

21 hours ago, vv3k70r said:

On 12/11/2020 at 11:04 AM, foamyesque said:

Depends on the bridge...

Decent bridge should be build of stone or wood like Romans did. It works - do not fix it. As You see improvments create issues - do not improve! I like my cave!

Pretty sure steel is easer than wood to bend, yes.

[vv3k70r]

2 hours ago, Bej Kerman said:

Pretty sure steel is easer than wood to bend, yes.

Yes - it is easier. Wood is a composite deliverging stiffnes. Try to bend wood on break press.

It is even better with stone.

I know a lot about bending steel, I get paid for this. Nobody would me to bend wood, I guess there are reasons (but Iknow how to do this - steam help doing this).

Edited December 12, 2020 by vv3k70r