Cory M

Nice work!

Looks good to me. The deflection numbers seem reasonable for the load. The only thing that I would consider changing is replacing the point loads in the head on crash with a distributed load along the bar, I think that would be more realistic although it may not change the deflection of the door bars much so it isn't a big deal.

Thanks a lot for taking the time to do this.

bruinbro

Can you give me some spatial coordinates of the joints or a stick sketch with dimensions? I can also model the bend radius' so include them.

Bro

bruinbro

I'm not sure that would be a valid scenario. What would impact the tube along it's length? Or are you saying the car would crumple to the point that the entire A-pillar structure and front would press against the vertical tube? Anyway, here's the results:



Bro

Geo

Ah, but this is a good example why good analysis is more than numbers. The sill tube, at least in my car, is there to prevent some car from submarining under the middle of the X and intruding into the cockpit.

Thanks for the clarification on the scale. That makes more sense to me now.

Geo

Sure. It'll take me a little while, but I can certainly do that.

M758

Dang I can't view pics at work. Darn firewall.

bruinbro

E-mail me at bruinbro@sbcglobal.net and I'll send them to you.

Bro

kurt M

Good thread, good input by many, good stuff. This is why Rennlist is stands out.

Note where the max loading of an X is in ether a side or angle load impact. The center. I would thing that this would be a good place for a TACO flat X or not. It would be interesting to see the deformation of the rest of the frame work that the X is attached to. My bet is that in many cars the X is stronger than what it is mounted to.

bruinbro

If you are referring to the cage as a whole, it'll be forthcoming as soon as someone gives me some dimensions and a design. If that wasn't what you were referring to, then look at the vertical tubes. They are part of the analysis and are only restrained at their ends.

Thanks for the kudos,

Bro

RedlineMan

Bingo! Like I said earlier, the Factory is usually a good resource for smart ideas. The don't do things by accident. Witness the Cup Car reinforced "Pyramid X."

Bingo Again! Any door bar is not worth spit if the sides of the hoops are not somehow braced. They will simply implode. Hence the use of knee knockers and lateral main hoop tubes.

bruinbro

Shall I continue?






BTW, is there a limit on the number of pages a thread can have? Should I make a new thread?

Bro

Geo

Oh my....

You haven't seen Ghettoracer's "Open Letter" thread.....

https://rennlist.com/forums/showthre...ht=open+letter

RedlineMan

OK...

George is not afraid of ignorance. I will be brave and not be afraid of utter density. Just to make sure, for my technically challenged mind. The main numbers in the value column are the amount of deflection. The -00/01/02 are the number of places the decimal point is moved to refelect the actual measured value?

I'm sure there must be a reason they display it that way.

bruinbro

Oh...never mind.

Bro

bruinbro

Brave souls abound in this forum! The numbers are shown in the default format; I'm so used to it that I didn't bother changing to something more appropriate to this discussion. I'll change to xxx.xx format for the future charts. You are correct, the exponents reflect the position of the decimal point.

Bro