Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Hydrodynamic bearings are presenting a large and deep research domain with an overall lack of investigation in the case of vertically mounted ones which complicates their applicability. These bearings are characterised by a complex behaviour as a self-excited instability known as oil whip which is a major concern of Sulzer Ensival Moret Belgium, a well-known pump manufacturer. This topic introduced the design of a tribological test rig for the experimental analysis of hydrodynamic bearings. The work objectives are the experimental analysis of hydrodynamic bearings based on their respective dynamic behaviour and the related validation of the test rig in terms of its validity for the dynamic analysis. To achieve both objectives, the work is divided in a theoretical and experimental part. The theoretical part treats the general bearing theory including so-called experimental identification techniques. The second part treats the experimental dynamic analysis of different bearings based on their respective whirl motion and the extraction of the stiffness coefficients from conducted measurements. At the other side, this part treats the validation of the test rig.

Test Rig --- Dynamic Analysis --- Hydrodynamic Bearing --- Ingénierie, informatique & technologie > Ingénierie civile

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Proceedings of the Pavement Mechanics Symposium at the 15th ASCE Engineering Mechanics Conference, held in New York, New York, June 4, 2002. This Geotechnical Special Publication contains 15 technical papers covering recent advances in the characterization and modeling of materials used in pavement systems. Topics include: subgrade soil and aggregate base/subbase materials characterization, asphalt concrete mixes and their constitutive modeling, pavement systems modeling, and use of artificial neural networks in pavement modeling. The analysis methods include both finite and discrete element modeling techniques, artificial neural networks, microstructural analysis, stiffness matrix approach for dynamic pavement analysis, and curve fitting and statistical parameter estimation techniques. Different methods of laboratory and field testing are included, namely: triaxial, asphalt tension, asphalt x-ray tomography imaging, asphalt binder, nondestructive pavement, accelerated pavement, and field bender element method. Engineers working within geotechnical and transportation facilities, who have a special interest in pavement mechanics, will find this publication of particular interest.

Road materials --- Pavements, Asphalt --- Soil mechanics --- Materials characterization --- Pavements --- Construction materials --- Asphalt pavements --- Material mechanics --- Discrete element method --- Dynamic analysis --- Network analysis --- Materials characterization --- Pavements --- Construction materials --- Asphalt pavements --- Material mechanics --- Discrete element method --- Dynamic analysis --- Network analysis

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Nonlinear behaviours are inherent to today’s aerospace industry due in part to the many contemporary constraints. This master thesis focuses on the study of such a nonlinearity by investigating the behaviour of a piccolo tube subjected to different types of external excitations. For this purpose, experimental tests are conducted on the corresponding physical structure on the one hand. On the other hand, similar results are attempted to be obtained using NI2D, a numerical simulation software adapted to the study of nonlinearities. This study is also in the continuation of results obtained in previous analyses. To this purpose, the structure is studied when subjected to sine sweep and randoms excitations. Methods are also implemented to extract and compare the stress levels to which the tube is subjected. The obtained results confirm the previous sine sweep findings. The methods used also allow a good correspondence between the two types of results for random excitations. Limitations must, however, be taken into account, in this case, when nonlinearity is reached due to a numerical over-representation of harmonics triggering. Finally, similar stress levels can be achieved for numerical tests and simulations outside resonance peaks. However, due to discrepancies, other numerical methods should be considered to obtain the stresses in the frequency band of the resonance peak, such as directly computing this data on a whole time signal. This could moreover allow the correspondence of the two types of stress results for random excitation.

nonlinear, --- vibration --- vibrations --- piccolo --- piccolo tube --- Experimental --- Numerical --- Dynamic analysis --- sinesweep --- random excitation --- NI2D --- nonlinearity --- stress --- strain --- Ingénierie, informatique & technologie > Ingénierie aérospatiale

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

The paper offers a non-probabilistic framework for representation of uncertainty in the context of a simple linear-quadratic model of fiscal adjustment. Instead of treating model disturbances as random variables with known probability distributions, it is only assumed that they belong to some pre-specified compact set. Such an approach is appropriate when the decision maker does not have enough information to form probabilistic beliefs or when considerations for robustness are important. Solution of the model in the minimax sense when disturbance sets are ellipsoids is obtained and the application of the method is illustrated using the example of Portugal.

Fiscal policy --- Tax policy --- Taxation --- Economic policy --- Finance, Public --- Econometric models. --- Government policy --- Macroeconomics --- Public Finance --- Production and Operations Management --- Statistical Decision Theory --- Operations Research --- Optimization Techniques --- Programming Models --- Dynamic Analysis --- Computational Techniques --- Fiscal Policy --- Macroeconomics: Production --- Debt --- Debt Management --- Sovereign Debt --- Public finance & taxation --- Output gap --- Fiscal multipliers --- Fiscal stance --- Public debt --- Fiscal consolidation --- Production --- Economic theory --- Debts, Public --- Portugal

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This paper examines the relationship between openness and within-country regional inequality across 28 countries over the period 1975-2005, paying special attention to whether increases in global trade affect the developed and developing world differently. Using a combination of static and dynamic panel data analysis, we find that while increases in trade per se do not lead to greater territorial polarization, in combination with certain country-specific conditions, trade has a positive and significant association with regional inequality. In particular, states with higher inter-regional differences in sector endowments, a lower share of government expenditure, and a combination of high internal transaction costs with a higher degree of coincidence between the regional income distribution and regional foreign market access positions have experienced the greatest rise in territorial inequality when exposed to greater trade flows. This means that changes in trade regimes have had a more polarizing effect in low and middle-income countries, whose structural features tend to potentiate the trade effect and whose levels of internal spatial inequality are, on average, significantly higher than in high-income countries.

Agriculture --- Comparative advantage --- Comparative advantages --- Competitiveness --- Dynamic analysis --- Econometric analysis --- Economic geography --- Economic growth --- Economic integration --- Economic Theory & Research --- Emerging Markets --- Exports --- Free Trade --- GDP --- GDP per capita --- Human capital --- Income --- International Economics and Trade --- International trade --- Macroeconomic policies --- Macroeconomics and Economic Growth --- Middle income countries --- Private Sector Development --- Purchasing power --- Real GDP --- Regional Economic Development --- Rent seeking --- Trade Policy