Go Back   Team-BHP > Under the Hood > Modifications & Accessories


Reply
 
Thread Tools Search this Thread
Old 6th October 2010, 13:37   #46
Senior - BHPian
 
pramodkumar's Avatar
 
Join Date: Mar 2006
Location: Gods own country
Posts: 1,991
Thanked: 857 Times
Infractions: 0/1 (5)
Default

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
pramodkumar is online now   Reply With Quote
Old 6th October 2010, 13:42   #47
BHPian
 
konjaril's Avatar
 
Join Date: Oct 2009
Location: Pune
Posts: 282
Thanked: 60 Times
Default

Quote:
Originally Posted by west View Post
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!

Last edited by n_aditya : 6th October 2010 at 16:28.
konjaril is offline   Reply With Quote
Old 6th October 2010, 13:46   #48
BHPian
 
west's Avatar
 
Join Date: Feb 2005
Location: India
Posts: 273
Thanked: 48 Times
Default

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.

Last edited by west : 6th October 2010 at 13:49.
west is offline   Reply With Quote
Old 6th October 2010, 13:52   #49
Senior - BHPian
 
pramodkumar's Avatar
 
Join Date: Mar 2006
Location: Gods own country
Posts: 1,991
Thanked: 857 Times
Infractions: 0/1 (5)
Default

Quote:
Originally Posted by west View Post
(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
pramodkumar is online now   Reply With Quote
Old 6th October 2010, 14:06   #50
BHPian
 
west's Avatar
 
Join Date: Feb 2005
Location: India
Posts: 273
Thanked: 48 Times
Default

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
west is offline   Reply With Quote
Old 8th October 2010, 14:53   #51
BHPian
 
Fantasy's Avatar
 
Join Date: Sep 2010
Location: Vancouver
Posts: 122
Thanked: 0 Times
Default

Quote:
Originally Posted by west View Post
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.
Fantasy is offline   Reply With Quote
Old 8th October 2010, 17:28   #52
BHPian
 
konjaril's Avatar
 
Join Date: Oct 2009
Location: Pune
Posts: 282
Thanked: 60 Times
Default

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..

Last edited by konjaril : 8th October 2010 at 17:33.
konjaril is offline   Reply With Quote
Old 8th October 2010, 18:50   #53
BANNED
 
Join Date: May 2008
Location: Hyderabad
Posts: 28
Thanked: Once
Default

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 is offline   Reply With Quote
Old 8th October 2010, 19:18   #54
BANNED
 
Join Date: May 2008
Location: Hyderabad
Posts: 28
Thanked: Once
Default

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
Davis.K is offline   Reply With Quote
Old 8th October 2010, 22:10   #55
BHPian
 
konjaril's Avatar
 
Join Date: Oct 2009
Location: Pune
Posts: 282
Thanked: 60 Times
Default

Quote:
Originally Posted by Davis.K View Post
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

Last edited by konjaril : 8th October 2010 at 22:24.
konjaril is offline   Reply With Quote
Old 9th October 2010, 06:52   #56
BHPian
 
Fantasy's Avatar
 
Join Date: Sep 2010
Location: Vancouver
Posts: 122
Thanked: 0 Times
Default

Quote:
Originally Posted by konjaril View Post
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..
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?
Fantasy is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pics: Carbon Fiber Seat - How it was handmade for FSAE Rehaan Technical Stuff 28 11th October 2015 14:26
My Honda DIO!! My very Own Bumblebee, now with Carbon Fiber! Cyrus43 Motorbikes 62 19th April 2012 12:30
Legality of my Yoshimura Carbon Fiber sound levels netchef Superbikes & Imports 16 24th April 2008 14:32
Mercedes SLC Class - All Carbon Fiber 500 hp to go against Audi R8 1Day The International Automotive Scene 1 31st January 2008 13:52


All times are GMT +5.5. The time now is 17:47.

Copyright 2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks