Detailed analysis and test correlation of a stiffened composite wing panel

Nonlinear finite element analysis techniques are evaluated by applying them to a realistic aircraft structural component. A wing panel from the V-22 tiltrotor aircraft is chosen because it is a typical modern aircraft structural component for which there is experimental data for comparison of results. From blueprints and drawings supplied by the Bell Helicopter Textron Corporation, a very detailed finite element model containing 2284 9-node Assumed Natural-Coordinate Strain (ANS) elements was generated. A novel solution strategy which accounts for geometric nonlinearity through the use of corotating element reference frames and nonlinear strain displacements relations is used to analyze this detailed model. Results from linear analyses using the same finite element model are presented in order to illustrate the advantages and costs of the nonlinear analysis as compared with the more traditional linear analysis. Strain predictions from both the linear and nonlinear stress analyses are shown to compare well with experimental data up through the Design Ultimate Load (DUL) of the panel. However, due to the extreme nonlinear response of the panel, the linear analysis was not accurate at loads above the DUL. The nonlinear analysis more accurately predicted the strain at high values of applied load, and even predicted complicated nonlinear response characteristics, such as load reversals, at the observed failure load of the test panel. In order to understand the failure mechanism of the panel, buckling and first ply failure analyses were performed. The buckling load was 17 percent above the observed failure load while first ply failure analyses indicated significant material damage at and below the observed failure load

WELFARE IMPLICATIONS OF THE WOOL ACT

A model of the U.S. sheep industry is estimated and simulated to determine the impact of the wool incentive program on actors in U.S. sheep product markets. The simulation analysis indicates that U.S. sheep producers and lamb and wool consumers are the programÂ’s gainers while lamb and wool exporters and taxpayers are its losers. Net societal losses averaged $26.4 million per year during the 1980-85 period, considering U.S. as well as exporter interests. This loss is about 2.5% of average U.S. consumer expenditures on lamb and wool over the period.Agricultural and Food Policy, Livestock Production/Industries,

MANURE HANDLING COSTS AND THE COMPETITIVENESS OF PORK PRODUCTION

Simulations of possible regulation-related manure handling costs are compared to base scenario costs for the three main regions and phases of modern hog production over widely varying scale levels. The base scenario confirms previous research suggesting that in Iowa net benefits occur at small scale levels from injecting slurry stored in an outside earthern basin for corn production using a phosphorus standard. Increased transportation costs result in Iowa costs surpassing costs in Utah at higher scale levels, while costs in North Carolina are highest at all scale levels. Requiring systems to be lined and covered in Iowa and North Carolina results in proportionately greater increased costs per head in North Carolina. Adding the requirement that manure be applied according to a phosphorus standard increases costs proportionately more in Iowa at larger scale levels, but not at all at the smallest scale, and costs in Iowa surpass those in North Carolina at the largest scale. The results of all scenarios underscore the advantages enjoyed by Utah in manure handling because scales of operation there are among the largest.Livestock Production/Industries,

New Interactive Solar Flare Modeling and Advanced Radio Diagnostics Tools

The coming years will see routine use of solar data of unprecedented spatial and spectral resolution, time cadence, and completeness in the wavelength domain. To capitalize on the soon to be available radio facilities such as the expanded OVSA, SSRT and FASR, and the challenges they present in the visualization and synthesis of the multi-frequency datasets, we propose that realistic, sophisticated 3D active region and flare modeling is timely now and will be a forefront of coronal studies over the coming years. Here we summarize our 3D modeling efforts, aimed at forward fitting of imaging spectroscopy data, and describe currently available 3D modeling tools. We also discuss plans for future generalization of our modeling tools.Comment: 4 pages; IAU Symposium # 274 "Advances in Plasma Astrophysics"; typo remove

IMPACT OF CHANGING CONSUMER PREFERENCES ON WILLINGNESS-TO-PAY FOR BEEF STEAKS

Consumer/Household Economics,

Energy Partitions and Evolution in a Purely Thermal Solar Flare

This paper presents a solely thermal flare, which we detected in the microwave range from the thermal gyro- and free-free emission it produced. An advantage of analyzing thermal gyro emission is its unique ability to precisely yield the magnetic field in the radiating volume. When combined with observationally-deduced plasma density and temperature, these magnetic field measurements offer a straightforward way of tracking evolution of the magnetic and thermal energies in the flare. For the event described here, the magnetic energy density in the radio-emitting volume declines over the flare rise phase, then stays roughly constant during the extended peak phase, but recovers to the original level over the decay phase. At the stage where the magnetic energy density decreases, the thermal energy density increases; however, this increase is insufficient, by roughly an order of magnitude, to compensate for the magnetic energy decrease. When the magnetic energy release is over, the source parameters come back to nearly their original values. We discuss possible scenarios to explain this behavior.Comment: ApJ in press; 11 pp, 6 figs; 3 on-line animation

REVEALED COMPARATIVE ADVANTAGE AND THE MEASUREMENT OF INTERNATIONAL COMPETITIVENESS FOR AGRICULTURAL COMMODITIES: AN EMPIRICAL ANALYSIS OF WOOL EXPORTERS

Trade liberalization and laissez-faire economics are altering the structure of agricultural production and trade. The principle of comparative advantage, a classic tenet of economics, is a useful tool for understanding the future of world agriculture. This study employs a "Revealed Comparative Advantage" approach to investigate patterns of comparative advantage among six major wool exporting countries.International Relations/Trade,