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Mechanical Engineering. 1998;120(11):60-64. doi:10.1115/1.1998-NOV-1.
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The U.S. Department of Energy is reducing various risks through its Office of Industrial Technologies (OIT), which shares the cost of developing and implementing technologies that promise to save energy, reduce emissions, and increase productivity of the US steel industry. The OIT signed a compact with the American Iron and Steel Institute and the Steel Manufacturers' Association in May 1995 to collaborate with the U.S. steel industry on three critical research and development areas: process efficiency, recycling, and environmental engineering. Researchers at Oak Ridge National Laboratory in Tennessee developed the nickel aluminide alloy for the rollers, which were centrifugally cast by Sandusky International in Sandusky, OH. This material has superior temperature resistance, which gives it longer service life in the annealing furnace than conventional stainless steel. A phosphor-based sensing technology being tested at Burns Harbor will enable steelmakers to accurately measure the temperature of highly reflective steel strips whose emissivity can skew the readings of optical pyrometers.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 1998;120(11):66-71. doi:10.1115/1.1998-NOV-2.
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This article examines the growing usefulness of computer-aided engineering (CAE) programs for the design of electronics packaging. CAE combined with expert interpretation, can help manufacturers quickly satisfy demand for increasingly small yet reliable products. Currently, three classes of software specifically support electronics packaging design: integrated computer-aided design (CAD) CAE software, general-purpose CAE software, and specialty CAE software solutions. The integrated CAE software emphasizes automatic creation and updating of finite-element-analysis (FEA) models based on CAD geometry. The effectiveness of this associativity between CAD and FEA depends on the product behavior to be evaluated and the quality of implementation. CAE simulation can calculate the maximum acceptable loads on pins, as well as the vibration characteristics of components. Solids-based CAD helps detect interference problems across components, as in these exploded views of a disc drive and a headset. While several general-purpose CAE suppliers permit engineers to build customized environments for automating model creation, specialty suppliers such as Pacific Numerix deliver the specific automated capabilities and connector libraries.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 1998;120(11):72-75. doi:10.1115/1.1998-NOV-3.
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American Society of Mechanical Engineering’s (ASME) risk-based inspection methodologies are being used to optimize and prioritize equipment overhaul and maintenance, and upgrade decisions. Hartford Steam Boiler Inspection and Insurance Co. (HSB) collaborated with ASME in developing these guidelines, and it used the ASME methodologies to develop its risk-based decision tools for steam turbine generators. The ASME Risk-Based Inspection Guidelines define five primary steps in developing risk-based programs. These are system definition, qualitative risk assessment, system assessment ranking, inspection program development, and economic optimization. In order to differentiate between turbines and generators in several types of service, the team designed a questionnaire that requires the owner or operator to identify equipment design features, monitoring capabilities, past operating and failure history, as well as current operating experience, inspection, and maintenance practices. The STRAP program is presently in the beta-testing phase, where 30 different turbines representing eight different manufacturers and three different industries have been analyzed. Full implementation of the program is expected to occur in the fall of 1998.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 1998;120(11):76-77. doi:10.1115/1.1998-NOV-4.
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This article discusses that event-simulation software can help engineers improve the safety of a military transport vehicle, while reducing the number of prototypes and shortening the design cycle. US Army's Tank and Automotive Command (TACOM) unit brought the truck's frame design to AM General with recommendations for a rollover protection structure. The AM General design team created plans for a T-shaped configuration to be added to the original truck frame that would protect occupants during a rollover accident. AM General stress analyst performed finite element analysis with Mechanical Event Simulation, including both Linear and Nonlinear Stress Analysis software from Algor Inc. of Pittsburgh. When the prototype asses its laboratory test, AM General will immediately manufacture an additional 20 units for both physical and field testing. This may include an armored variant for field testing in Bosnia, an area with rugged topography. TACOM plans to modify other M 939/A1 / A2 series trucks on an as-needed basis; they will install the rollover protection structures on trucks in use where conditions like rough terrain make rollover accidents more likely.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 1998;120(11):78-80. doi:10.1115/1.1998-NOV-5.
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This article explores a set of inner and outer brush seals capable of bidirectionally restricting flows in a wave rotor, which has been successfully fabricated and tested. Advantages cited for the wave rotor include enhanced efficiency, rotor material temperatures lower than the peak gas temperatures, lower speed rotation with reduced stress, simple robust construction, and rapid transient response. A cross-sectional view of the rotor shows the cavities and placement of the brush seals. No definitive tests were undertaken during the break in stage or during the testing; thus, one can only conclude that the bristles wore significantly, and the rotor coating showed little evidence of tracking other than being highly polished with some spottiness. Some powder debris was found in the exhaust port. The principles of bidirectional brush design can be applied to all brush configurations, providing bidirectional capability, controlled seal stiffness/damping, bristle spread, flutter, protection from foreign object damage, and a double labyrinth-orifice at essentially the same cost as a conventional brush seal construction.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 1998;120(11):82-83. doi:10.1115/1.1998-NOV-6.
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This article illustrates that while crash analyses have been carried out with success, a crush analysis is much more difficult to achieve. In a crash analysis, the inertia effects smooth out the nonlinearities and deficiencies in the solution algorithms. In a crush test, it takes about 10 to 30 seconds to crush the car to the required maximum displacement of the steel plate. Since the critical time step for explicit time integration in a crash code is on the order of microseconds, millions of time steps must be used to perform the analysis in a physically correct manner. With sufficient numerical experimentation, involving changes to the load application speed and perhaps to other parameters, LSDYNA results can be obtained that would match laboratory test results, but such experimentation requires a lot of time and computational effort. A solution that corresponds to the actual physical conditions and is computationally efficient is much more desirable. Such a computed solution is given above for a Ford Taurus model. The calculated crush results obtained with ADINA using implicit integration compare favorably with the laboratory test results.

Commentary by Dr. Valentin Fuster

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