Audi Gets Edge over BMW and Benz with…New Lightweight Spring

[Rainer271]

It is common knowledge that Audi has ambitions of becoming the world’s highest-selling premium automaker by the end of the decade. Toward that end, the brand has already announced a gigantic spending spree of €22 billion ($30 billion) for development costs of new models.
In the company’s quest to make its vehicles more competitive against rivals from Germany and beyond, it has just announced an advancement in suspension spring technology.

Currently, Audi’s springs are made of steel, as are those of many automakers. The new springs set to debut in “an upper mid-size model” in late 2014 are made from glass fiber-reinforced polymer, or GFRP. The result will be more precise vehicle dynamics, less vibration, and more cabin comfort.

GFRP springs are light green. While its fiber strands are thicker than those of steel springs, it is 40 percent lighter. With all things being equal, a steel spring weighs 2.7 kg (6.0 lb), while a GFRP spring weighs 1.6 kg (3.5 lb). Together, four GFRP springs can reduce a car’s weight by 4.4 kg (9.7 lb), half of which is important unsprung mass. Just as notable, GFRP springs do not corrode and are not affected by chemicals – which may make them longer lasting than traditional counterparts.

Audi co-developed GFRP with an unspecified Italian supplier. The construction technique of GFRPs are not altogether dissimilar from those of carbon fiber reinforced plastics – another important technology automakers are using to make their models stronger, lighter, and more dynamic. GFRPs are made from long glass fibers twisted together along with an epoxy resin. A machine spirals on more fibers for added strength before it is baked in an oven at 100 degrees Celsius (212 degrees Fahrenheit).

It is unclear which model the new springs will debut on, but the 2015 Audi A7 is a distinct possibility.

 

[klier]

Edge over BMW with it's CF plant in America? LOL, I think not. Nice try Audi.

The tech is cool, and it's a nice development. The article and name in particular is rather silly.

 

[Mars1965]

It is common knowledge that Audi has ambitionsof becoming the world’s highest-selling premium automaker by the end of the decade. Toward that end, the brand has already announced a gigantic spending spree of €22 billion ($30 billion) for development costs of new models.
In the company’s quest to make its vehicles more competitive against rivals from Germany and beyond, it has just announced an advancement in suspension spring technology.

Currently, Audi’s springs are made of steel, as are those of many automakers. The new springs set to debut in “an upper mid-size model” in late 2014 are made from glass fiber-reinforced polymer, or GFRP. The result will be more precise vehicle dynamics, less vibration, and more cabin comfort.

GFRP springs are light green. While its fiber strands are thicker than those of steel springs, it is 40 percent lighter. With all things being equal, a steel spring weighs 2.7 kg (6.0 lb), while a GFRP spring weighs 1.6 kg (3.5 lb). Together, four GFRP springs can reduce a car’s weight by 4.4 kg (9.7 lb), half of which is important unsprung mass. Just as notable, GFRP springs do not corrode and are not affected by chemicals – which may make them longer lasting than traditional counterparts.

Audi co-developed GFRP with an unspecified Italian supplier. The construction technique of GFRPs are not altogether dissimilar from those of carbon fiber reinforced plastics – another important technology automakers are using to make their models stronger, lighter, and more dynamic. GFRPs are made from long glass fibers twisted together along with an epoxy resin. A machine spirals on more fibers for added strength before it is baked in an oven at 100 degrees Celsius (212 degrees Fahrenheit).

It is unclear which model the new springs will debut on, but the 2015 Audi A7 is a distinct possibility.

It is already used on the Renault Megane RS 275 Trophy-R. Italian manufacturor is Sogefi. (BTW ZF already has these springs to).

 

[SCOTT27]

This is the Laser light scenario all over again. Just wait till next year.
Its the competition that drives you...

 

[Deckhook]

It is already used on the Renault Megane RS 275 Trophy-R. Italian manufacturor is Sogefi. (BTW ZF already has these springs to).

I'm not doubting you here but it would sound odd if Audi co-developed the technology to allow another manufacturer the rights to use it ahead of them.

 

[Mars1965]

I'm not doubting you here but it would sound odd if Audi co-developed the technology to allow another manufacturer the rights to use it ahead of them.

Convinced?
http://www.autoevolution.com/news-g-image/renault-megane-rs-275-trophy-r-sets-new-nurburgring-lap-record-75436/210717.html#sjmp

 

[Giannis]

It's amazing what you can do with GFRP. I've even seen it substituting the classic steel reinforcement bars for use in reinforced concrete structures.

On the other hand, GFRP is a material very very different from steel. I can write more details if anyone is interested.

 

[martinbo]

It's amazing what you can do with GFRP. I've even seen it substituting the classic steel reinforcement bars for use in reinforced concrete structures.

On the other hand, GFRP is a material very very different from steel. I can write more details if anyone is interested.

Yes please - I am very interested in learning more.

 

[Deckhook]

Convinced?

I didn't doubt you only that it sounded odd if Audi had co-developed the technology that they would have allowed someone else to use it first that's all.

 

[Giannis]

Yes please - I am very interested in learning more.

The main drawback of GFRP materials is the high creep coefficient. In plain english, under constant load you should have a constant displacement, but displacement increases somehow, instead. All materials are exhibiting creep behavior, including steel and concrete, but it is not of importance, as it is very small. In GFRP it's quite significant.

Creep isn't a problem under dynamic loading, when the car is driven. But what about when the car is parked/ standing still? I am sure that these springs won't last long - a lifetime, actually, like steel springs. They could need replacement every couple of years, and they won't be cheap. Also, I am not sure that since creep is so important in GFRP applications that the dynamic characteristics of the car won't be affected over time.

Simply put, their characteristics will alter over time, as the car stands still.

 

[Deckhook]

^Sounds like not much of a benefit long term over steel unless they have somehow developed a way to counter this.

 

[Giannis]

^Sounds like not much of a benefit long term over steel unless they have somehow developed a way to counter this.

Bob, I highly doubt that there is a way to counter the creep effect. It's a characteristic of the material. It's like saying you found a way to alter the thermal expansion coefficient of, let's say, aluminum. You can't.

Look, GFRP as a material has certain drawbacks and certain good aspects. In my field, it's used as an alternative to CFRP, when retrofitting a structure. For example, you could enfold a column in order to increase its axial load capacity. If you want to do it even for permanent loads, you use CFRP and it costs about 100€ per column in my area. If you only want to increase the column's axial load capacity only under earthquake excitation (only for the event of an earthquake, that is), you can use GFRP, because it will work only under a small duration dynamic loading. For static loading it's useless. Plus it costs quite a lot less than CFRP - you can retrofit a column for less than 60€.

Then again, I am a structural engineer, therefore I am only familiar with what concerns my field of application. I've read countless papers on CFRP and GFRP applications for seismic retrofit, but noone is yet certain about how this stuff works. There are design equations, but with high uncertainty.

Despite the fact that I've worked with both (C and GFRP) materials in both academic and field application cases, I've grown a high distrust against them.

 

[Wolfgang]

The W126 with the optional hydro suspension (487) doesn't have springs.
But the nitrogen spheres have a creep effect and need to be replaced about every ten years or so.

 

[Deckhook]

^^ It sounds like any benefits will be short lived and a replacement will be required on a regular basis. Not so sure the average punter will be willing to pay every couple of years unless the cost isn't that dramatic.

 

[Giannis]

^^ It sounds like any benefits will be short lived and a replacement will be required on a regular basis. Not so sure the average punter will be willing to pay every couple of years unless the cost isn't that dramatic.

Cost is a relative quantity. If you get many things in return, then maybe cost isn't that much important.

In this case, the reduction in unsprung mass can be quite important. An educated guess is that a GFRP spring weights less than a kilo. A typical steel spring weights a few kilos.

It's a question of priorities

 

[Iamnotme]

Since we're talking about springs, this article from Autoexpress seems to be relevant to the suject at hand:

EXCLUSIVE: Audi plots power-generating hybrid suspension

R&D boss confirms Audi is close to harnessing energy from suspension to power its cars
Audi is in the advanced stages of developing a power-generating suspension system, Auto Express can reveal. The idea stems from the now common technology of brake energy regeneration, as Audi looks to harness wasted energy and cut fuel consumption.

At the launch of the new Audi A3 e-tron plug-in hybrid, Audi R&D chief Dr Ulrich Hackenberg confirmed Audi has successfully developed a 'generator suspension' that will eventually be available in production models.

Dr Hackenberg explained: 'What people don't realise is that dampers get very hot. When working hard over a bumpy road, the dampers are perhaps 100 to 125 degrees. This energy is wasted as heat into the atmosphere. So, we will replace the suspension with a generator.'

Though Hackenberg was coy on specific details, it's possible Audi will incorporate a rotating generator unit into the damper, which is spun as the suspension compresses. Audi's R&D supremo said the captured electrical energy will be stored in batteries to power the car's hybrid drive system, though it's also possible the extra current could be used to juice the car's ancillary electrical systems. Such a setup would reduce resistance on the combustion engine and improve fuel mileage.

Dr. Hackenberg also hinted how the system could be advanced for more performance-orientated cars. 'Because we can send energy back into the damper, you will have an independently variable suspension. This can [counteract] roll [of the car's body].

It's unclear when the energy suspension will make either a concept car or production debut, but Dr Hackenberg did pithily hint the technology would be great news for the UK, due to how hard the dampers have to work on Britain's pothole-scarred roads.

 

[KiwiRob]

The W126 with the optional hydro suspension (487) doesn't have springs.
But the nitrogen spheres have a creep effect and need to be replaced about every ten years or so.

Neither did the Austin 1100.

 

[JHF]

Audi Develops New Lightweight Spring for Use on Fuel-Conscious 'Ultra' Models

Earlier this year, Audi introduced a fuel-efficient sub-brand for the A4, A5 and A6 called “ultra,” and it looks like it could have one more trick up its sleeve in the name of maximizing fuel economy. To cut as much weight as possible from its cars, Audi has announcedplans to install a new set of glass fiber-reinforced polymer (GFRP) suspension springs for use on its upcoming vehicles.
Although Audi didn’t go as far as to say which car this technology will debut on, the press release confirmed that it will be part of the German automaker’s “ultra” program and “will appear in an executive class Audi model before the end of the year.” The GFRP springs weigh just 40 percent of what conventional steel springs weigh. To put this into actual numbers, each GFRP spring weighs 1.6 kilograms (3.5 pounds) compared to a steel spring, which weighs 2.7 kg (almost 6 pounds). In total, these new spring will help shave 4.4 kilograms (9.7 pounds from the overall curb weight, and about half of that comes out of the car’s unsprung weight.

“The GFRP springs save weight at a crucial location in the chassis system. We are therefore making driving more precise and enhancing vibrational comfort,” said Dr. Ulrich Hackenberg, Member of the Board of Management for Technical Development at AUDI AG.

In addition to weight reduction, Audi says that the construction of these new GFRP springs is a greener process that requires less energy than producing steel springs. The core of the GFRP spring is just a few millimeters in diameter and it consists of fibers that twisted and bonded together with epoxy resin. Additional fibers are then wrapped around the core at varying angles to increase the strength and the entire spring assembly is then cured at high temperatures.

Audi claims that the GFRP springs can be more finely tuned to a specific application, and the material does not corrode or affected by harsh chemicals.


Audi Develops New Lightweight Spring for Use on Fuel-Conscious 'Ultra' Models