Stronger, Lighter, Cheaper

By Catherine
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Written by Catherine Bolgar*
NanomaterialIndustrial materials involve trade-offs. Desirable qualities tend to come with undesirable flip sides. Strength, for example, tends to come at the expense of ductility, or the ability to stretch without breaking. So the stronger something is, the more it’s likely—ironically—that when it does fail, it fails completely.

What if you could have both high strength and ductility? This is likely to happen, thanks to breakthroughs in new materials, many of which involve building the materials in innovative ways at the atomic level.

A microscopic view of metals would show them as made up of grains. Stronger materials have smaller grains, and more ductile materials have larger grains, explains Yuntian Zhu, professor of materials science and engineering at North Carolina State University in the U.S. However, if you make an entire part with small grains for high strength, it might fail catastrophically under stress.

When you make any structure, you want at least 5% ductility. The more ductility, the safer it is. But the downside is that the strength comes down,” he says.

Dr. Zhu found that by forming steel with larger grains inside and gradually moving to smaller grains at the surface, the result has both strength and ductility. This gradient structure is found in nature, he says, for example in plants and bones.

Near the surface, it’s harder. As you go deeper it gets softer,” Dr. Zhu says. “Nature just puts raw materials where they’re needed most. It minimizes the material cost. In nature, that proves useful.”

Using a gradient structure in steel could extend the lives of bridges, ships and oil pipelines, for instance.

Hardening steel by working it is another technique to make steel that’s both strong and ductile. Twinning-induced plasticity—or TWIP—steel is strengthened by twisting, deforming, bending, flattening or hammering it. At Brown University, researchers twisted cylinders of TWIP steel to deform the molecules on the surface. The molecules in the center remained unaffected, providing the flexibility, while the surface got harder, providing more strength.

Usually when something is strong, it’s also heavy. What if you could have both strength and lightness?

Nicholas X. Fang, associate professor of mechanical engineering at the Massachusetts Institute of Technology, has developed a foam material that can withstand a weight 10,000 times greater than its own.

“It’s as light as aerogel, yet as stiff as a hammer,” he says. Much of the space between the structures is void, which is why the material is so light.

The material uses nanotubes or nanowires a quarter of the size of a human hair to form a network or structure that takes away the load. “Each of the nanotubes under the load are under compression or a stress state,” Dr. Fang says. “But they turn out to be quite resilient. In the lab, we compress the samples to 60% of their original size.”

Dr. Fang is contemplating applications for this new material. The material could absorb impact while reducing weight, for example, in a tennis racket that’s lighter than aluminum alloy, yet able to deliver similar strength against a bouncing ball.

It could be important for microstructures in batteries,” he adds. Batteries receive a lot of shock when charging, which causes the structure to suddenly expand—and corrode. “If we could use this material in a battery, we could solve the challenge of quick charging,” he says.

Satellites also could benefit from a material that’s very lightweight, to reduce the payload, yet able to withstand shocks.

Nanowires in three-dimensional structures also are being explored by researchers at the University of California, Davis. By combining atoms of semiconductor materials—such as gallium arsenide, gallium nitride or indium phosphide—into nanowires that form structures on top of silicon surfaces, they hope to create a new generation of fast electronic and photonic devices.

The nanowire transistors could be used to make sensors that can withstand high temperatures and are easier to cool.

polymer surfaceSomething everybody wants to be strong yet shatterproof is their smartphone screen. Researchers at the University of Akron in Ohio have come up with a transparent layer of electrodes on a polymer surface that could stand up to repeatedly having adhesive tape peeled off and retain its shape after being bent a thousand times. The new film may be cheaper to make than the coatings of indium tin oxide now used on smartphone screens.

In fact, in a number of cases, the materials or processes themselves aren’t necessarily expensive, which makes them likely to be adopted relatively quickly.

It’s actually quite easy,” says Dr. Zhu about making steel with a gradient structure. “The only thing is, can we do it in an industrial way or develop a technology to do it?” The cost is likely to be very low, and some in industry already are trying it.

“It might take a few years for widespread adoption,” he says.

The super-strong foam material developed by Dr. Fang isn’t expensive, but the manufacturing process is—at least for now. Only a few centimeters of the material can be made, which is a limitation of the printing process, not the material itself, Dr. Fang says. “Now it’s important to connect the dots to make it into a larger format at lower cost.”

*For more from Catherine, contributors from the Economist Intelligence Unit along with industry experts, join The Future Realities discussion.

A Chronicle of Futures Foretold

By Catherine
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Written by Catherine Bolgar

Wouldn’t it be nice to have a crystal ball to warn us when the next crisis will happen?

Buffalo on Wall Street

While it isn’t a crystal ball, Swiss university ETH Zurich has developed a scientific platform to predict when bubbles develop. Didier Sornette, professor of entrepreneurial risks at ETH Zurich, created the university’s Financial Crisis Observatory in 2008 as a reaction to the global financial crisis.

I became very angry about what I read that predicting such a crisis wasn’t possible,” he says. “We knew a crisis was coming. We knew this impression of great wealth and mastering of the economy was an illusion.”

Dr. Sornette notes that he doesn’t predict the crash. “We diagnose the bubble before the end, when a crash confirms it existed,” he says.

Normal up-and-down cycles aren’t the same as the booms and busts of bubbles. The existence—or nonexistence—of bubbles ends up in arguments about what is normal vs. abnormal, compared with history, price-equity ratios or an excessive growth rate of the stock market.

What should the normal growth rate be: 5%, 15%, 20%? What could justify that last year the return was 20%? Was it irrational or was it new technology?” Dr. Sornette says. “People find reasons that justify the observed price.”

Rather than pick a number, Dr. Sornette’s model looks for superexponential growth. Regular growth is exponential because of the effects of compounding. With superexponential growth, the growth rate itself is growing.

The bubble is when rate of return accelerates,” he says. “It’s a positive feedback loop. In normal circumstances, the higher the price, the lower the demand. In a bubble, the higher the price, the larger the demand and therefore there’s a larger subsequent growth rate. It’s due to a crowd effect, or herding, because it’s so tempting to imitate the others and to run after the bonanza of the time.”

By coming up with a scientific model with verifiable metrics, Dr. Sornette hopes the resulting evidence will help the “is-it-a-bubble-or-not” debate move from being philosophical or political to being scientific. Similarly, it wasn’t until the existence of the ozone hole was scientifically proven that an international agreement to ban chlorofluorocarbons was adopted.

William White, who was a member of the executive committee of the Bank for International Settlements, and some of his BIS colleagues warned that a crisis was about to hit in 2007.

It seems what we have to focus on is the systemic fragilities that are building up in the economy, as opposed to looking for any trigger point,” he says. “My way of looking at it is increasingly to see the economy as a complex adaptive system. It shares the characteristics of other complex adaptive systems: we know they are inherently vulnerable to crises and that crises occur on regular basis, though the literature says big crises come infrequently but little crises come frequently. In something as complex as the international financial system, things are going to go wrong.”

Cyclical downturns are “events that clear out the system,” he says. “We probably have had 25 years of too little tolerance for downturns. Every time one threatened or happened, we just threw huge amounts of monetary intervention and expansion at it.”

Economic Bubble

The longer bubbles persist and the larger they are, the more likely they are to spread into other sectors. “It’s because of the wealth effect,” Dr. Sornette says. “During a bubble everybody feels rich.”

This makes it hard to stop bubbles. People love them while they’re inflating, and policy makers don’t want to declare an end to the party. One goal of scientifically declaring the existence of a bubble is to force the hand of policy makers to take actions that will deflate or plateau the bubble before it expands to the point of triggering a big, messy crisis.

Financial crises are particularly difficult because the fears of sudden failures can turn into a sort of reverse bubble, with losses feeding new losses. In addition, “a bank that is in bad shape finds it difficult to raise new equity and so is reluctant to make loans, which hurts the real economy,” says Paul Klemperer, economics professor at Oxford University in the U.K.

To remedy this, contingent convertible bonds were designed so that, when things go bad for a bank, they turn into shares or equity. The question is, “‘when does the conversion happen?’ In practice, when regulators say so,” Dr. Klemperer says. “Can we trust regulators to say so in time? We need these bonds to convert automatically, so regulators have to take action to stop conversion, not start it.”

He and co-authors Jeremy Bulow, professor of economics at Stanford University, and Jacob Goldfield, a former senior partner at Goldman Sachs, have proposed a new form of hybrid capital for banks, equity recourse notes, which automatically convert debt into equity when a bank loses market capitalization.

For Dr. Sornette, diagnosing bubbles with scientific metrics is another way to automatically help regulators and policy makers act: “They will do the right thing, if they’re forced to by the scientific evidence.”

For more from Catherine, contributors from the Economist Intelligence Unit along with industry experts, join The Future Realities discussion.

Improving the Reliability of Consumer Electronics Products Through Realistic Simulation

By Harish
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Realistic simulation for Electronic products

Early product failures and product recalls are very costly. They result in loss of revenue, litigation, and brand devaluation among others. Hardware recalls are often costlier than software recalls as software patches can be easily downloaded and installed once flaws come to light. But recalls and early product failures tend to happen over and over again. Why? Because engineering teams are constantly under the gun to improve product performance, reduce form factors, and reduce time to market, all while cutting costs. In order to mitigate risk engineers need to develop a deeper understanding of the product behavior under real operating conditions and quickly evaluate design trade-offs based on overall system behavior.

Physical tests provide an excellent means to understand product behavior. However, physical testing is expensive and time consuming. Simulation provides a cheaper and faster alternative to physical tests. It is critical to strike the right balance between physical tests and simulation during product development. In order to get the maximum bang for your buck, simulations should be deployed starting early in the design cycle when physical prototypes are not available and the design is not fully developed. The earlier you find flaws, the earlier you can fix them. Since the cost of fixing flaws grows exponentially through the design cycle (figure below), identifying and fixing design flaws early in the design cycle is super critical.

Relative Cost of fixing errors in embedded Systems

Relative cost of fixing errors in embedded systems

Not all simulation tools are created equal. You don’t need any answer. You need the right answer. For that, you need simulation tools that most closely depict reality. And you need answers fast. Hence you need product testing and validation tools with industry leading physics and solver technology to obtain accurate solutions faster in order to help you improve product design, ensure product reliability and reduce time to market. Accurate depiction of material behavior and physics of failure are essential to obtaining realistic results. Such capabilities are critical in predicting the behavior of materials such as glass, adhesives, and polymers that have high propensity for damage.

Consumer electronic products, especially mobile and portable devices such as smartphones, tablets and laptops, are subjected to a variety of operating conditions. The devices need to be designed to protect them from damage. Engineers need to ensure that “portable” doesn’t mean “breakable.”

Tablet drop

The challenge is to design a light-weight product that can withstand not just the loading cycles associated with regular usage, but also abusive loading scenarios that are encountered less frequently (According to surveys and insurance claim statistics, drop and water damage constitute the two most frequent causes of damage for mobile devices.). Simulation should be employed at the ideation, product development, and failure analysis stages in order to improve product quality and reduce time to market. Refer to this  case study to learn how a leading manufacturer of consumer electronics used simulation to improve the keystroke feel and to enhance frame rigidity while reducing weight .

Tablet drop simulation

While drop during daily usage is a concern for mobile devices, transportation drops are the main concern for office equipment. The engineers are faced with the challenge of identifying the structural members that are most susceptible to damage and to improve their damage resistance while reducing the overall weight of the structure. Refer to the ebook below to know how a leading manufacturer of office equipment designed a low cost printer that can withstand a series of transportation drop tests.

The examples above provide a snapshot of applications leveraging SIMULIA Abaqus technology   to successfully improve product durability while satisfying other constraints such as weight and cost.

More example related to  how engineering teams are using virtual testing to predict stresses, optimize design performance and reduce time to market can be read in  this ebook .



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