Honeycomb cores have also been used in aerospace carbon fiber composites, such as the structure and blades of Sikorsky Aircraft's S-97 RAIDER helicopters and, reportedly, in the shell of Virgin Galactics' SpaceShip Two. A similar honeycomb sandwich structure is used in some parts of Boeing 787's Dreamliner.
The new material's honeycomb core is covered on both its top and bottom with glass fiber mats, then sprayed with the Baypreg system, which contains a flame retardant and may optionally also contain cut glass fibers. The component is placed in a compression mold while it is still moist and is pressed at a temperature of 130°C. The polyurethane system foams slightly and binds the components together. After about two minutes, the part can be removed from the mold and deburred.
Components as large as four square meters in area can be produced, yet they have excellent dimensional stability, allowing the parts to be installed in the final assembly with a high level of precision. "By using this new material, we can reduce the component’s weight by over 35 percent -- and cut costs by 30 percent," said Jan Kuppinger, a Fraunhofer ICT scientist, in a press release.
Bayer's Baypreg spray system has been used in automotive applications for producing panorama roof modules, spare tire covers, and the floor of a car's trunk. The team optimized the standard fiber spraying manufacturing process by developing a mixing chamber that allows more complex structures to be produced in any required size. The prototype diesel engine housing measures approximately 4.5 meters long and more than 2 meters wide.
The diesel engine housing prototype was produced as part of the PURtrain project, which is funded by the German Federal Ministry of Education and Research (BMBF). The prototype has passed its first strength test; the next step is field tests. If the prototype passes those tests, the team expects the material to also be useful in applications such as roof segments, side flaps, and wind deflectors for automobiles and commercial vehicles.
Ok, so it's jumbled, but that's the point. We've heard so much about the use of composites in the automotive sector and in aerospace, even with large-scale boats and yachts, but not so much in trains. Improved access to more efficient and cost-effective mass transportation is equally as important as alternative energy sources and lightweighting vehicles as part of green energy strategies. This is a cool development. Any big deals yet for the technology?
Beth, it's still a prototype in the testing phases, and no potential contract awards were mentioned. But since it's the German government funding the project, one might guess that it could be used in German trains, as well as the other applications mentioned: roof segments, side flaps, and wind deflectors for automobiles and commercial vehicles.
Ann, it seems like this composite has the performance advantages -- light weight, good structural capacity -- that engineers want. How does it measure up to more traditional materials in terms of cost?
This makes no sense at all. The locomotive must be heavy as the drawbar force is the product of the weight and the coefficient of friction of the wheels on the rails. The limit is the permanent deformation of the wheels and the rail. For more drawbar force, use multiple engines, totalling more weight.
Everyone has missed the point here, because the original article is not very clear. There is no locomotive, what is being described is a DMU (diesel multiple unit) passenger car. They are not common in the USA any more - there are just three commuter systems (Austin TX, San Diego's Sprinter, Portland OR Westside) that use them. The Marin County SMART will also use them.
There used to be lots of them in the USA - the Budd RDC (Rail Diesel Car) could be found across the country.
DMUs are very common elsewhere in the world, especially the UK and Europe. The major problems with adoption in the use are 1) the FRA treats them as locomotives, with the required inspection schedules, and 2) international designs do no meet FRA rules for impact (buffing) strength.
Typically these cars have two diesel engines - often derived from truck engines - mounted UNDER the passenger compartment floor. The cover is intended to keep debris and weather OUT and any leakage IN. The RDCs had no such covers, which probably did not help their reliability.
Drawbar pull, weight, etc are not really the issues here. DMUs are self-powered, although some are intended to pull a single unpowered trailer. They are NOT designed to pull a train of unpowered cars.
skranish, thanks for your comment. The Fraunhofer press release http://www.fraunhofer.de/en/press/research-news/2012/march/building-lightweight-trains.html discusses this in the context of trains (including in the headline), calls this suitable for diesel engine housings on trains, and mentions both the engine and the cars, although it doesn't mention whether the cars are powered.
"This housing is located beneath the passenger compartment, i.e. between the car and the tracks. Not only does it shield the engine against flying stones and protect the environment from any oil that might escape, but in the event of a fire, it also stops the flames from spreading, thus meeting the flame retardant and fire safety standards for railway vehicles."
That pretty well describes a DMU. The "multiple unit" part of DMU means that more than one car can be coupled together an run as train.
An engineer from the UK company GEC Marconi once said to me, and I quote, "only a trainspotter would use the term DMU". Let me guess - you are from the UK, at one time in your youth you used to stand on railway platforms photographing trains, and you owned, or own, a Hornby model railway.
Sorry to disappoint you, but I have never even been to the UK, and I do not fit the usual definitions of trainspotter (not a term used in the US), railfan, or foamer. My childhood photos do not include any of trains.
The rather confusing term "diesel light rail" is sometimes used in the US. I looked at the Austin Capitol Metro and North County Transit Sprinter websites, and neither offers any description of their trains. The Austin Metro and Sprinter websites both include numerous linked documents containing the term "DMU". The Vandalpedia pages for the rail lines describes Austin as a "tram train" - definitely not a term in the US lexicon, and Sprinter is described as a DMU.
The SMART website describes their trains: "SMART will use Diesel Multiple Unit (DMU) vehicles manufactured in Rochelle, Illinois, by Sumitomo Corp. of America/Nippon Sharyo. The DMU is quieter and cleaner than conventional locomotive-hauled equipment. These self-contained rail cars include on-board engines and are capable of using alternative fuels such as waste-derived bio-diesel."
The Portland Westside Express website does not directly describe their trains, but numerous PDF documents buried in the website use the term DMU. The Portland railcars, the only ones of their type, are FRA compliant and can run on mixed traffic rail lines without requiring temporal separation from freight trains.
Battar and skranish, thanks for the discussion about terminology. I'd never heard of a DMU before, but like most of our readers, I'm not an expert in this area. Ultimately, though, the focus of the article was what the materials can do in this application, and that was pretty clear.
Many of the new adhesives we're featuring in this slideshow are for use in automotive and other transportation applications. The rest of these new products are for a wide variety of applications including aviation, aerospace, electrical motors, electronics, industrial, and semiconductors.
A Columbia University team working on molecular-scale nano-robots with moving parts has run into wear-and-tear issues. They've become the first team to observe in detail and quantify this process, and are devising coping strategies by observing how living cells prevent aging.
Many of the new materials on display at MD&M West were developed to be strong, tough replacements for metal parts in different kinds of medical equipment: IV poles, connectors for medical devices, medical device trays, and torque-applying instruments for orthopedic surgery. Others are made for close contact with patients.
New sensor technology integrates sensors, traces, and electronics into a smart fabric for wearables that measures more dimensions -- force, location, size, twist, bend, stretch, and motion -- and displays data in 3D maps.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.