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Science U.S. Army Tests Composite-bodied Humvee
Brandon Hill (Blog) - September 21, 2007 8:44 AM
Print E-mail del.icio.us 65 comment(s) - last by winterspan.. on Sep 23 at 11:41 PM

TPI Composites General Manager Kevin Weldi poses with the new Humvee  (Source: Associated Press)
New composite Humvees shed 900 pounds of weight

Humvees are synonymous with transporting troops on the ground during times of war. The ubiquitous workhorses are also pretty lacking when it comes to protection from enemy fire and improvised explosive devices (IEDs).

The U.S. Army in conjunction with AM General Corp. and TPI Composites Inc. are looking to composite materials to give its soldiers a better chance at surviving treacherous working conditions on Iraq.

Its latest test bed is a Humvee that features a frame and body made of composite materials. Resin material is used to bond together balsa wood, carbon reinforcements, fiberglass and foam. The use of composite materials on the Humvee shaves 900 pounds off the usual 10,000 to 12,000 pound vehicle weight.

"We can put the strength where we need it," said TPI Composites CEO Steven Lockard. "Every pound of weight we save, that weight is being added back to the vehicle in armor and mine-blast protection."

Additional armor could be placed under and around the cabin area of the Humvee to protect the passengers, while the composites materials alone could be used for the hood and fenders.

Predictably, the new composite-bodied Humvees are slightly more expensive than their conventional counterparts and the Army still hasn't made a firm commitment to purchasing the vehicles.

With that said, TPI Composites is fully prepared should the Army give the company the green light. "We could ramp up pretty quickly to most any volume that would be desired," said Lockard.

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By DeepBlue1975 on 9/21/2007 9:02:06 AM , Rating: 4
That all these new light weight and high resistance materials being researched, can make their way into the street cars market.

I'm tired of having to buy always a new car that is inevitably heavier while featuring almost the same size than the previous generation ones.

A compact or mid sized european / japanese car from the 1995-2000 era weighted roughly the same as what now weights a small or mini car from the same brand, which I find really annoying.




By sdifox on 9/21/2007 9:56:15 AM , Rating: 5
quote:
As is the case with the Humvee and IEDs, composites don't add much strength when it comes to crash protection. Therefore you're going to want to have quite a bit of steel still in your car in order to maintain safety.


Huh? You mean those F1 drivers crashing their carbon fibre cars into the wall and walk away is a miracle?


By TomZ on 9/21/2007 10:06:43 AM , Rating: 1
No miracle there - but there is obviously a strong focus on safety. In a way it's kind of a controlled environment.

http://atlasf1.autosport.com/news/safety.html


By abhaxus on 9/21/2007 1:37:13 PM , Rating: 3
So Robert Kubica hitting the wall in Montreal going 190mph and decelerating at almost 50G was a controlled environment? :)


By hrah20 on 9/21/2007 3:40:25 PM , Rating: 2
Let's keep the eye on the ball here, anything that helps soldiers to survive a mine,bomb or rpg is great I'm just hoping here that it doesn't take too long for the army to approve this, yesterday on HBO I was watching a documentary called : (ALIVE DAY MEMORIES: HOME FROM IRAK)they were showing the soldiers injuries, what they went through, and the videos from the insugents related to each soldier, the videos of the explosions where disturbing to say the least, and they show you the magnitude of those explosions, IF there is something to help them survive and have a better chance of getting out alive, I say it's GREAT !!!.


By FITCamaro on 9/21/2007 10:38:15 AM , Rating: 4
These humvees aren't being made out of straight carbon fiber either. They're using fiberglass, balsa wood, carbon reinforcements (probably some carbon fiber), and foam. So don't compare them to a high performance race car who's chassis costs more than one of these Humvees.

And yes, carbon fiber can be very brittle. Even NASA has raised this concern. And those drivers are surviving because they're all but bolted to their seats and are surrounded by a roll cage. Drag cars have all steel roll cages and are going 100+ mph faster than F1 cars and their drivers survive just fine without any carbon fiber.


By sdifox on 9/21/2007 12:05:06 PM , Rating: 3
quote:
These humvees aren't being made out of straight carbon fiber either. They're using fiberglass, balsa wood, carbon reinforcements (probably some carbon fiber), and foam. So don't compare them to a high performance race car who's chassis costs more than one of these Humvees.


But what we are talking about here is just replacing the body panels more than anything else with the composite material. The weight saving then gets moved to more armour. Sounds good to me.


By 91TTZ on 9/21/2007 1:05:23 PM , Rating: 3
quote:
And yes, carbon fiber can be very brittle. Even NASA has raised this concern.


NASA raised the brittleness issue with the reinforced carbon-carbon leading edges of the Shuttle wings. This is a different material than carbon fiber. They both have carbon fibers, but the bonding material is different.


By DEVGRU on 9/21/2007 11:53:31 AM , Rating: 2
Yeah, and each one of those F1 cars cost millions - with hundreds of millions spent in R&D, testing, and manufacturing. And the (amazing) protection carbon fiber does provide an F1 car is (99%) engineered to perform in the lateral plain (front, side, rear).

Costs aside, (I know that wasn't your point per sa) carbon fiber (and its close cousin Kevlar) aren't known for its anti-ballistic, kinetic, or thermal resistance as far as stopping 1-2000 lbs. of C4, HMX, RDX, or Semtex explosives in a shaped charge directly beneath a vehicle, be it a Hummer or flipping a 60-ton M1 Abrams onto its back like a turtle.


By sdifox on 9/21/2007 12:07:43 PM , Rating: 2
quote:
by DEVGRU on September 21, 2007 at 11:53 AM

Yeah, and each one of those F1 cars cost millions - with hundreds of millions spent in R&D, testing, and manufacturing. And the (amazing) protection carbon fiber does provide an F1 car is (99%) engineered to perform in the lateral plain (front, side, rear).

Costs aside, (I know that wasn't your point per sa) carbon fiber (and its close cousin Kevlar) aren't known for its anti-ballistic, kinetic, or thermal resistance as far as stopping 1-2000 lbs. of C4, HMX, RDX, or Semtex explosives in a shaped charge directly beneath a vehicle, be it a Hummer or flipping a 60-ton M1 Abrams onto its back like a turtle.


But they are not talking about replacing armour with composite, just the skin. At least that is what I read.


By sdifox on 9/21/2007 12:10:41 PM , Rating: 2
I meant to say structural and skin, but adding more armour with the weight saved.


By afkrotch on 9/21/2007 7:43:45 PM , Rating: 2
quote:
Huh? You mean those F1 drivers crashing their carbon fibre cars into the wall and walk away is a miracle?


If you haven't noticed, the cars also feature large open areas, allowing for a natural crumple zone within them. Also the cars use many types of materials. Aluminium, titanium, magnesium, and of course, carbon fibre. For the most part, the frame and body panels are created using a layering of carbon fibre. Course none of this has anything to do with hummers, as creating this layering of carbon fibre is really expensive.

I don't expect the military to pay $1 mil per hummer.


By DeepBlue1975 on 9/21/2007 10:23:39 AM , Rating: 3
Not necessarily true:

For example, by these days its very usual that car designers make the front of the car more flexible as to be able to absorb impact energy, but reinforce the part where people are to make it as little deformable as possible.

As someone replied you, there are materials out there which are lighter than steel but yet more resistant, like carbon fibre, so that steel shouldn't be a mandatory part (were it not for the low cost of steel versus better materials).

Not always a harder frame means higher crash protection (well, it might be better for the vehicle to be less deformable, but it is not for the passengers that, then, will have to stand most of the impact's energy transferred directly to their bodies instead of having the body of the car absorb that as much as possible).

At least I'd rather get a car that gets destroyed in a crash but keeps me alive, instead of one that gets little damage but also gives me little probability of surviving :D


By Amiga500 on 9/21/2007 11:12:35 AM , Rating: 3
Carbon Fibre is excellent for crash protection - I don't what gave your the impression of anything otherwise.

While they can be brittle, and extremely weak 'out of plane' - by cross weaving during lay-up you will get an extremely strong and flexible (if needs be) component. The amount of energy CF can absorb is tremendous - and that is the critical thing in crashes, absorbing energy.


By FITCamaro on 9/21/2007 9:09:05 AM , Rating: 2
Thats because of all the safety equipment and electronics for said safety equipment. Instead of people learning how to drive, we just cram our cars full of airbags, anti-roll technology, etc.

There was a lot fewer accidents and deaths in the days when cars were made of steel and all you had was a seat belt (if you had one).

I vote for going back to said cars. Then people might actually be afraid of getting in an accident again for a reason other than their insurance rates going up.


By TomZ on 9/21/2007 9:23:10 AM , Rating: 3
I agree with everything, except for the part that there were fewer accidents "when cars were made of steel." The statistics don't seem to support your conclusion.

http://www.iihs.org/news/2006/iihs_news_081006.pdf


By Shoal07 on 9/21/2007 9:24:14 AM , Rating: 2
Speed limits were also signifigantly lower across the board, which is directly attributable to lower death per accident ratios back then. Do you also want to drive 35mph everywhere? There's little anything can do to save you once you start getting over 55mph... especially 75mph+ - hit a tree at those speeds and all the steel in the world will still crumple like a can (with you in the middle).


By Egglick on 9/21/2007 10:06:47 AM , Rating: 2
Studies have shown that lowering the speed limit doesn't positively impact accident rates. I also highly doubt that the material of a vehicles body has any effect on whether you crash said vehicle.

I think higher accident rates are mainly the result of significantly more cars and people on the road.