[pramodkumar]

Hey sunil,

Relax man, its not worth to comment on some fact less comments made by people who don't know jack about designing, you have a regular fan following for your thread and that itself is a big deal for readers like me. Any one who is familiar with a monocoque design concepts of the modern day passenger car will not comment about body panels like the fenders, bumpers and bonnets adding strength or structural rigidity to the overall vehicle, any body who has the slightest idea about crumple zones will never talk like this, any ways its time to update your thread

@ West the fastest road legal sport cars were made of FG before CF was invented, does that mean they are potential coffins on wheels.

Peace


Pramod

[konjaril]

Originally Posted by west

And i do have core knowledge on composites, If you think CF is impact resistant, you are ignorant. . If its 3 layers and 1/2 inch gel coat, i assumed it by 5 mm thickness you said on video (7 layer roving 600gsm- standard size in good hand layup is 5mm).If its gelcoat you applied load is taken on that . Get some thing from this or >>> I dont care, but dont make these videos on public forums. Please do data analysis and see for your self.

no issues at all man you dont have to shower me the knowlege on composites i know a small bit about them too..i just found it too ignorant from your side to just comment i am not a good designer. you are 'nobody' to do that

As to your comment on not making videos and doing data analysis its my wish what i make and dont so please dont even go near telling me what to do and not to. Dont bother to answer my comment as i am out!

@pramod thanks for atleast understanding pramod because it just hurts that you spend your life trying to make something and people just say that you are not worth it...
Cheers!

[west]

Im not in mood to argue or comment on how much i know , you know stuff. You can make my ignorance fade away with your knowledge , please do that. You can start with the energy dissipation channel, if some thing hits the panel. (till now i think crumples zones absorb energy and bend)

Thank you.

[pramodkumar]

Originally Posted by west

(till now i think crumples zones absorb energy and bend)

Thank you.

Dear friend,

Crumple zones are not limited to panels alone, there are other components as well.


Pramod

[west]

Yes exactly pramod, but they are designed in a way that chassis takes minimal stress usually in a linear way. Thats mono. Thats why unidirectional fibre is used in f1 or rockets

[Fantasy]

Originally Posted by west

As per the video of konjaril, it good for marketing illiterates. What really happened in the video is you hit a small area for a split second on a 7 layers of woven rovings covering around 14 sq mtrs area, the shock is carried and rippled away to the edges. Th force is not sufficient to deform the part, keep in mind metals creep, fiber dont they break. And using a iso resin with good elastic properties to bind fiber is the cause of this nature. Also the part is not hinged, so the shock passed, made the bonnet bounce. It wont be the case if you fix the bonnet and if a car hits on fender for more than a split second. Shocks will pass on to the passengers through chassis, and hinges attached to chassis & panel shears & breaks.

This is the worst design of composite in real time. You might have seen formula one cars, how the debre flies if in impact, all particles dissipate energy in all directions , not allowing the tub get the shocks.

In this design, its same as old ambassodor cars, with thick skins, only change is we used fibre glass which is lighter than steel.


Hence Mr. konjaril please dont consider your panel to be good and put lifes in danger mainly neck injuries. I dont consider you a good designer from this.. Please get your core knowledge right. I think some one also pointed out the same in your other thread.

the design shown in the video which stands up to bumps in real world driving is a good design and the video is great for marketing. simply put. poorly constructed fiberglass parts even carbon/kevlar parts are brittle and do not hold up to every day driving conditions.

i'm willing to bet that if there was an impact great enough to affect the people riding within the vehicle that part would "break" apart as you put it requiring replacement. hoods and fenders are not considered structural parts on a vehicle. again if there was an impact large enough to impact the passengers then the chassis and structural metal would take the force of the impact long before the "dangerous" hood would cause any damage to the passengers.

[konjaril]

Very rightly put fantasy, bonnet fenders,bumpers all those come under the skin of a vehicle body they dont play any part with the structural members in a car. anyways when something is thought out of the box there would be skeptics hell bent on proving them wrong.. Right the same way when some blokes around earlier tried to prove that earth is round and how all the scholars criticized them for that

BTW what will people do to Chris Bangle for making this car then? please listen to what he explains..

YouTube - The new BMW Gina Light Visionary concept car

[Davis.K]

I can unerstand what you saying, but you need to design so that stress & fatigue is taken by what they are designed for. In BMW case they know it and tested . So thats very different.

Im not sure FRP panels and steel shouldnt be taken the same way, unless they are designed the for, other wise our automotives will be filled with composites.. I know "plastic stuff what?? " in india. My point is if can define stress channel every thing could be right. Well that fancy video of yours might be good marketing tool for a static object rather than dynamic.

Here we have a 80s chassis of conty if im not mistaken, I think what west might say is also partly right, but he didnt define the context.

[Davis.K]

And lets not fight over every thing, we dont even have any scientific data to analyse. So every thing is just theoritical assumptions in this context. and good effort konjaril, every day we learn some thing, lets stick to it.

PS: I have been working for some time in advanced composites , and im have some knowledge on material science & i dont take sides. good luc

[konjaril]

Originally Posted by Davis.K

And lets not fight over every thing, we dont even have any scientific data to analyse. So every thing is just theoritical assumptions in this context. and good effort konjaril, every day we learn some thing, lets stick to it.

PS: I have been working for some time in advanced composites , and im have some knowledge on material science & i dont take sides. good luc

well yes friend i completely agree with ur point..and west didnt say anything otherwise too..i just didn't understand how he tagged me a bad designer..its my profession..

Well what i meant was that panels like bonnet, fenders are not structural components..u might have noticed that the conti's structural components are yet to come under the fiber glass body ..what my 'fancy' video proves is that the fiberglass composite is not as how people over the year have mistook it for...its light yet strong.

Also you dont see fiberglass on every OEM manufactured cars because of the hand layup process would be almost impossible for a mass production car i think you might know this as you have a knowledge on this field.Also composites are frightfully expensive for them to be seen on every car on the road.i am not challenging anybody's knowledge but i bet on it for a fact that once the manufacturing costs of carbon fiber comes down drastically you wont find metal body cars.

Also low number manufactured sports cars are today built in composites, you have fiberglass body corvettes, tvr's, lotus's etc. i have preferred fiberglass as they are extremely better to use for a one off project instead of using metal and making my car just a piece of heavy metal lump. and if you have the patience to go through my thread i have strengthened the chassis almost three times its original strength.There would be a roll cage, there would be structural stress members and they are still to come..

Having worked on a full carbon fiber body + carbon fiber chassis(tub) + carbon fiber component american sports car (yet to come) i can vouch for one thing ...Future is composites

[Fantasy]

Originally Posted by konjaril

Very rightly put fantasy, bonnet fenders,bumpers all those come under the skin of a vehicle body they dont play any part with the structural members in a car. anyways when something is thought out of the box there would be skeptics hell bent on proving them wrong.. Right the same way when some blokes around earlier tried to prove that earth is round and how all the scholars criticized them for that

BTW what will people do to Chris Bangle for making this car then? please listen to what he explains..
YouTube - The new BMW Gina Light Visionary concept car

keep up the good work. i'd love to see what other projects you have going on. practice definitely makes perfect. there is always new tech. and new resins on the market to ensure a quality product. i started working with fiberglass in the early 90's for car audio purposes. same with carbon which we got into the late 90's...prior to it being trendy. took a lot of trial and error. i've hand laid hoods and trunks and copied the factory design. not fun at all. i think the fumes from the resins are the worst part.

i have yet to try vacuum bagging parts out of carbon as we haven't had a need to just yet and it's not cheap to just play around with. have you?