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Sensors Provide Early Diagnosis Of Microcracks In Aircraft |
 Today's aircraft are in service virtually around the clock and must operate reliably and safely at all times. An active sensor system helps to detect concealed fatigue cracks in aircraft bodies, thus reducing maintenance times considerably.
If a tiny crack in the hull of an aircraft remains undetected for a long time, it can easily spread and put passengers’ lives at risk. Each component is therefore subject to international maintenance regulations: Aircraft bodies must be thoroughly inspected every 15 to 18 months, depending on the type of plane. This often requires the technicians to dismantle an aircraft’s interior lining – an expensive and time-consuming process involving several days of downtime in the hangar. Researchers at the Fraunhofer Institute for Structural Durability and System Reliability LBF in Darmstadt are developing a sensor system that allows engineers to continuously monitor the condition of their aircraft and detect any damage at an early stage.
The system is based on piezoceramic sensors that are attached to the aircraft body in a network pattern. What is special about these sensors is that they start to oscillate when a voltage is applied to them – and when they are subjected to pressure, they generate voltage. The scientists make use of both effects: While the piezo foils cause part of the hull to oscillate, the others measure the component’s response to this stimulation. “We investigated the oscillation behavior of damaged struts and rivets in an aircraft body and compared it with that of intact parts,” explains LBF project manager Dirk Mayer. “If a component is defective, it oscillates at a different frequency from one that is intact when stimulated by the piezoceramics – just as a cracked glass sounds different from an undamaged one when you tap it with your fingernail.” In this way, the researchers can accurately track down faults and monitor their development – be it fatigue cracks in the hull and wings, or rivets and other joining parts coming loose. This form of observation is also referred to as ‘structural health monitoring’ (SHM).
“With the help of this system, any damage behind the lining or in difficult-to-reach places can be identified quickly and easily, thus reducing maintenance times and inspection costs,” says Mayer. The researchers have already performed tests on a hull component in the laboratory, and are now implementing the new technology with standardized piezo and electronic components. The system will then also be suitable for use in vehicle manufacture or engine and plant construction.
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Dear Editor,
I hope you can help me or at least point me in the right direction. My neighbor just put up a huge CB Radio antennea, the thing is higher that the roof of his home, the problem is, now I have interference through our television set speakers. We can hear him speaking although it is not too clear. How can I fix the problem so that we can watch t.v. without hearing this noise? Any help you can give me would be greatly appreciated.
Sincerly,
Donna R.
Dear Donna,
If your neighbor's transmissions are interfering with your TV, the best thing for you to do is complain to the Federal Communications Commission. The FCC investigates cases of interference and they will determine if your neighbor's transmissions contain out-of-band signals. You might also try talking to your neighbor. If his antenna is for amateur radio rather than Citizens Band, "ham" radio operators have a policy of supplying a free filter for your TV in such cases.
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ElectronicDesignNet News
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We scan the wires, web sites, blogs and news media for the most interesting and relevant information, then summarize it for you in a convenient format, organized by topic areas during the week:
You can stay on top of things without wasting your precious time sifting through lots of noise. Subscribe to our digest and receive it in your eMail, or come to our site and read it in your web browser. Digest eMail subscriptions can be managed on the Newsletters tab of the "My Settings - Edit Profile" page once you register.
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Worldwide Software Piracy Rate Holds Steady At 35%, Global Losses Up 15% |
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Business News - Monday
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Tuesday, 15 May 2007 |
A new study reveals that 35% of the software installed in 2006 on personal computers (PCs) worldwide was obtained illegally, amounting to nearly $40 billion in global losses due to software piracy. Progress was seen in a number of emerging markets, most notably in China, where the piracy rate dropped ten percentage points in three years, and in Russia, where piracy fell seven percentage points over three years. These are among the findings of the fourth annual global PC software piracy study released today by the Business Software Alliance (BSA), an international association representing the commercial software industry. The study was conducted independently by IDC....more  (0) Comments |
Worldwide PDA Market Continues Downhill Slide As Major Vendor Exits The Market |
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Business News - Monday
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Tuesday, 15 May 2007 |
The worldwide handheld device (PDA) market opened the year with its thirteenth consecutive quarter of year-on-year decline as user interest continued to transition towards converged mobile devices and other consumer electronics devices. According to IDC's Worldwide Handheld QView, vendors shipped just over 900,000 handheld devices in the first quarter of 2007, 36.3% less than the previous quarter and 40.6% less than the same quarter a year ago. The decrease in shipments coincides with the announcement that one of the leading vendors, Dell, is leaving the industry.
"Dell's exit from the handheld device market underscores the market's decline," says Ramon Llamas, research analyst with IDC's Mobile Device Technology and Trends team. "The features found on a handheld device are not exclusive to handheld devices. Personal information management, the key feature that once distinguished handheld devices, can now be found commonly on converged mobile devices. The growing popularity of converged mobile devices combined with declining prices for laptop computers have put tremendous pressure on the handheld device market. The addition of multimedia and GPS features onto handheld devices did not stem their decline because standalone multimedia players and personal navigation devices grew in popularity. The growth in these other segments have come at the expense of the handheld device as vendors have responded eagerly with new, feature-rich products."...more (0) Comments |
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Cypress Introduces Programmable Clock Generator With Sub-75-ps Jitter |
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Product Showcase - Friday
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Tuesday, 15 May 2007 |
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Cypress Semiconductor introduced a low-jitter, single-chip programmable clock generator. The CY22180 clock offers a low period and cycle-to-cycle jitter output of below 75 picoseconds for its entire output frequency range, reaching as low as 60 picoseconds for the most commonly used frequencies. The low-jitter device delivers the precision clocking required by networking equipment such as routers and switches, as well as by consumer, communication and industrial applications. The CY22180 clock is available in field-programmable or factory-programmable options. (0) Comments |
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Flomerics Releases Flotherm Version 7 |
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Product Showcase - Friday
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Tuesday, 15 May 2007 |
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Flomerics has released Version 7 of its Flotherm electronics thermal analysis software featuring a new Response Surface Optimization capability that Flomerics believes is unrivalled in computational fluid dynamics (CFD) analysis software. Earlier versions of Flotherm included a sequential optimization capability allowing users to specify combinations of design parameters and iterate sequentially towards the best design. The new Response Surface Optimization goes further by fitting a 3D surface to the entire design space, enabling engineers to visualize the complete interaction of the design parameters with the design goal as well as identifying the optimum to a greater degree of accuracy....more (0) Comments |
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