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See detailComposite dark matter and direct-search experiments
Wallemacq, Quentin ULg

Doctoral thesis (2015)

Detailed reference viewed: 41 (12 ULg)
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See detailThe Composite Genome Of The Legume Symbiont Sinorhizobium Meliloti
Galibert, Francis; Finan, Turlough M.; Long, Sharon R. et al

in Science (2001), 293(5530),

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See detailComposite hydraulic modeling to design a complex dam spillway
Erpicum, Sébastien ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

Conference (2015, July 01)

The paper presents the application of a composite hydraulic modeling approach to the rehabilitation studies of a complex dam spillway. First, a physical scale model of the existing works has been built ... [more ▼]

The paper presents the application of a composite hydraulic modeling approach to the rehabilitation studies of a complex dam spillway. First, a physical scale model of the existing works has been built and operated. It enabled to define very accurately the actual discharge capacity and to validate a numerical model of the system. Second, the numerical model has been used to rapidly test several rehabilitation solutions. Finally, the final design has been validated and optimized using the physical model. The paper shows how composite hydraulic modeling enables to combine the inherent advantages of physical and numerical modeling approaches, which are complementary, while being beneficial to the delay as well as the quality of the analysis. [less ▲]

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See detailComposite joints in robust building frames
Jaspart, Jean-Pierre ULg; Demonceau, Jean-François ULg

(2008, July)

Recent events such as natural catastrophes or terrorism attacks have highlighted the necessity to ensure the structural integrity of buildings under exceptional actions. Accordingly, a European RFCS ... [more ▼]

Recent events such as natural catastrophes or terrorism attacks have highlighted the necessity to ensure the structural integrity of buildings under exceptional actions. Accordingly, a European RFCS project entitled “Robust structures by joint ductility” has been set up in 2004, for three years, with the aim to provide requirements and practical guidelines for the design of steel and composite structures under exceptional actions. In this project, the importance of the structural joints has been shown; as a particular case, these ones experience additional high tying forces after the loss of a column, as a result of the development of membrane forces in the beams located just above the damaged column. Moreover a reversal of moments occurs in some joints. In this paper design models for the evaluation of the mechanical properties of joints in such extreme situations are presented. References are made to recent tests on joints in isolation and joints in frames recently achieved at Stuttgart and at Liège University in the framework of the above-mentioned RFCS project. [less ▲]

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See detailComposite joints under M-N at elevated temperatures
Haremza, Cécile; Santiago, Aldina; Demonceau, Jean-François ULg et al

in Journal of Constructional Steel Research (2016), 124

The Eurocodes recognise robustness as a way to ensure the structural integrity of a building frame subjected to an unforeseen event and therefore to avoid a so-called “progressive failure” mode in extreme ... [more ▼]

The Eurocodes recognise robustness as a way to ensure the structural integrity of a building frame subjected to an unforeseen event and therefore to avoid a so-called “progressive failure” mode in extreme loading situations. However, few practical guidelines exist nowadays which would allow a designer to design a structure accordingly. Within the European RFCS ROBUSTFIRE project, the behaviour of steel and composite car parks subjected to localised fire leading to a column loss was investigated. Under such a scenario, the beam-to-column joints play a key role in the global structural response. Indeed, these joints, initially loaded in bending, may be subjected to elevated temperatures and to combined axial load “N”, bending moment “M” and shear forces “V”. In this paper, a methodology to predict the mechanical response of bolted composite beam-to-column joints at elevated temperatures under M-N is presented and validated through comparison with detailed numerical results and experimental tests. This methodology is based on an analytical method able to predict M-N resistance interaction curves for steel and composite joints and which is in full agreement with the component model recommended by the Eurocode. [less ▲]

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See detailComposite joints under M-N at elevated temperatures - Experimental investigations and analytical model
Demonceau, Jean-François ULg; Haremza, Cécile; Jaspart, Jean-Pierre ULg et al

in Proceeding of the Composite Construction VII conference (2013)

The Eurocodes recognise robustness as a way to ensure the structural integrity of a building frame subjected to an unforeseen event and therefore to avoid a so-called “progressive failure” mode in extreme ... [more ▼]

The Eurocodes recognise robustness as a way to ensure the structural integrity of a building frame subjected to an unforeseen event and therefore to avoid a so-called “progressive failure” mode in extreme loading situations. However few practical guidelines exist nowadays which would allow a designer to design a structure accordingly. Within the European RFCS ROBUSTFIRE project, the behaviour of steel and composite car parks subjected to localised fire leading to a column loss was investigated. Under such a scenario, the beam-to-column joints play a key role in the global structural response. Indeed, these joints, initially loaded in bending, may be subjected to elevated temperatures and to combined axial load “N” and bending moment “M”. In this paper, a methodology to predict the mechanical response of bolted composite beam-to-column joints at elevated temperatures under M-N is presented and validated through comparison to experimental tests conducted at the University of Coimbra. [less ▲]

Detailed reference viewed: 53 (5 ULg)
See detailComposite Manufacturing by Friction Stir Processing
Simar, Aude; de Meester, Bruno; Delannay, Francis et al

Conference (2012, October 29)

A new solid-state process developed recently on the same principles as Friction Stir Welding (FSW), Friction Stir Processing appear as a very promising technique for the production of metal matrix ... [more ▼]

A new solid-state process developed recently on the same principles as Friction Stir Welding (FSW), Friction Stir Processing appear as a very promising technique for the production of metal matrix composites and for tailoring materials properties. In the present work, this process has been applied to two different composite systems: (i) magnesium-matrix composites reinforced with carbon fibers, and (ii) copper-matrix composites reinforced with Y2O3 powder. Process optimization and mechanical properties of the composites are discussed in both systems. [less ▲]

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See detailComposite modeling to enhance hydraulic structures studies
Erpicum, Sébastien ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Proceedings of SimHydro 2012 (2012)

Physical modeling and numerical modeling are two efficient analysis approaches in hydraulic engineering. The interactive application of both methods is obviously the more effective response to most flow ... [more ▼]

Physical modeling and numerical modeling are two efficient analysis approaches in hydraulic engineering. The interactive application of both methods is obviously the more effective response to most flow problems analyses. Indeed, it enables combining the inherent advantages of both approaches, which are complementary, while being beneficial to the delays as well as the quality of the analysis. The paper presents the way composite modeling is applied for years at the HECE - Laboratory of Engineering Hydraulics (University of Liege) to enhance hydraulic structures studies. Besides numerical model validation for which experimental benchmarks constitute the first reliable data source, simultaneous application of both modeling approaches may be envisaged in three different ways. Composite modeling may be used to increase the scale factor of physical models by reducing the layout of the real structure to be modeled, to provide a better answer to specific problems than a single approach study or to maximize the efficiency of experimental tests by reducing the range of variation of the unknown parameters to be tested. For each of these three issues depicted in the paper, several examples show how the combined use of efficient numerical solvers together with physical scale models enables to increase the overall quality and scope of the analyses while decreasing the delays and possibly the costs. [less ▲]

Detailed reference viewed: 19 (2 ULg)
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See detailComposite modeling to enhance hydraulic structures studies
Erpicum, Sébastien ULg; Dewals, Benjamin ULg; Archambeau, Pierre ULg et al

in Houille Blanche (2012), 6

Physical modeling and numerical modeling are two efficient analysis approaches in hydraulic engineering. The interactive application of both methods is obviously the more effective response to most flow ... [more ▼]

Physical modeling and numerical modeling are two efficient analysis approaches in hydraulic engineering. The interactive application of both methods is obviously the more effective response to most flow problems analyses. Indeed, it enables combining the inherent advantages of both approaches, which are complementary, while being beneficial to the delays as well as the quality of the analysis. The paper presents the way composite modeling is applied for years at the HECE - Laboratory of Engineering Hydraulics (University of Liege) to enhance hydraulic structures studies. Besides numerical model validation for which experimental benchmarks constitute the first reliable data source, simultaneous application of both modeling approaches may be envisaged in three different ways. Composite modeling may be used to increase the scale factor of physical models by reducing the layout of the real structure to be modeled, to provide a better answer to specific problems than a single approach study or to maximize the efficiency of experimental tests by reducing the range of variation of the unknown parameters to be tested. For each of these three issues depicted in the paper, several examples show how the combined use of efficient numerical solvers together with physical scale models enables to increase the overall quality and scope of the analyses while decreasing the delays and possibly the costs. [less ▲]

Detailed reference viewed: 16 (4 ULg)
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See detailComposite smooth estimation of the state price density implied in option prices
Frasso, Gianluca ULg

in Kneib, Thomas; Sobotka, Fabian; Fahrenholz, Jan (Eds.) et al 29th International Workshop on Statistical Modelling, Göttingen, Germany, 2014, Proceedings (2014, July)

We propose a new semi-parametric approach for the estimation of the State Price Density (SPD) implied in option prices. Our procedure is inspired by a Penalized Composite Link Model (PCLM) approach and ... [more ▼]

We propose a new semi-parametric approach for the estimation of the State Price Density (SPD) implied in option prices. Our procedure is inspired by a Penalized Composite Link Model (PCLM) approach and ensures smooth and arbitrage-free estimates. [less ▲]

Detailed reference viewed: 19 (0 ULg)
See detailComposite steel-concrete joints in braced frames for buildings
Jaspart, Jean-Pierre ULg

in Composite steel-concrete joints in braced frames for buildings (1996)

Detailed reference viewed: 41 (2 ULg)
See detailComposite steel-concrete joints in frames for buildings: Design provisions
Jaspart, Jean-Pierre ULg

in Composite steel-concrete joints in frames for buildings: Design provisions (1999)

Detailed reference viewed: 33 (3 ULg)
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See detailComposite structures design for strength and stiffness with respect to ply thickness and/or fibers orientation
Bruyneel, Michaël ULg; Duysinx, Pierre ULg; Fleury, Claude ULg

in CHENG, Gen Dong (Ed.) Proceedings of the 4th World Congress of Structural and Multidisciplinary Optimization WCSMO4 (2001, June)

This paper presents an optimization approach that allows the design of composite structures under stiffness and strength criteria, with fibers orientations and plies thickness taken into account in the ... [more ▼]

This paper presents an optimization approach that allows the design of composite structures under stiffness and strength criteria, with fibers orientations and plies thickness taken into account in the same optimization loop. The approach is based on the sequential convex programming. An industrial application is presented. [less ▲]

Detailed reference viewed: 70 (3 ULg)
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See detailComposite structures optimization including non-linear finite element analysis, design and manufacturing considerations
Bruyneel, Michaël ULg; Grihon, Stéphane; Hudson, Leigh

in NAFEMS World Congress (2015)

Detailed reference viewed: 47 (2 ULg)
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See detailComposite structures optimization using sequential convex programming
Bruyneel, Michaël ULg; Fleury, Claude ULg

in Advances in Engineering Software (2002), 33(7-10), 697-711

The design of composite structures is considered here. The approximation concepts approach is used to solve the optimization problem. The convex approximations of the MMA family are briefly described ... [more ▼]

The design of composite structures is considered here. The approximation concepts approach is used to solve the optimization problem. The convex approximations of the MMA family are briefly described. Several modifications of these approximations are presented. They are now based on gradient information at two successive iterations, avoiding the use of the expensive second-order derivatives. A two-point fitting scheme is also described, where the function value at the preceding design point is used to improve the approximation. Numerical examples compare these new purely non-monotonous schemes to the existing ones for the selection of optimal fibers orientations in laminates. It is shown how these two-point based approximations are well adapted to the problem and can improve the optimization task, leading to reasonable computational efforts. A procedure is also derived for considering simultaneously monotonous and non-monotonous structural behaviors. The resulting generalized approximation scheme is well suited for the optimization of composite structures when both plies thickness and fibers orientations are considered as design variables. It is concluded that the newly developed approximation schemes of the MMA family are reliable for composite structures optimization. All the studied approximations are convex and separable: the optimization problem can then be solved using a dual approach. (C) 2002 Civil-Comp Ltd and Elsevier Science Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 39 (2 ULg)
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See detailLes composites à matrice métallique/céramique – De nouveaux procédés de fabrication pour de nouvelles applications
Mertens, Anne ULg; Lecomte-Beckers, Jacqueline ULg

Conference (2014, May 20)

A l’heure où la plupart des matériaux composites essentiellement structuraux sont faits d’une matrice à base polymère, les matériaux composites à matrice métallique ou céramique offrent de nouvelles ... [more ▼]

A l’heure où la plupart des matériaux composites essentiellement structuraux sont faits d’une matrice à base polymère, les matériaux composites à matrice métallique ou céramique offrent de nouvelles perspectives en termes de performances et de durabilité. Le présent exposé s’attache plus particulièrement à retracer les possibilités offertes par de nouvelles méthodes de mise en oeuvre telles que la friction-malaxage et les techniques d’impression 3D, aussi bien en termes d’amélioration des propriétés mécaniques des matériaux composites que des fonctionnalités inédites qui peuvent leur être conférées. [less ▲]

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See detailComposition and biological activities of the essential oil of Nigella sativa seeds isolated by accelerated microwave steam distillation with cryogenic grinding
Alkoul, R; Benkaci-Ali, F; Zerrouki, M et al

in American Journal of Essential Oils and Natural Products (2014), 1(3), 23-33

In this study, essential oil of Sahara Nigella sativa L. was extracted using a rapid extraction, the microwave steam distillation (MSD) and the cryogenic grinding (CG). Two procedures have been ... [more ▼]

In this study, essential oil of Sahara Nigella sativa L. was extracted using a rapid extraction, the microwave steam distillation (MSD) and the cryogenic grinding (CG). Two procedures have been investigated, the MSD1 (seeds inside of oven apparatus) and MSD2 (seeds outside of oven apparatus). Forty-six compounds were identified and significant differences in quantities of the major constituents were observed, mainly were thymoquinone (CLG: 331.82-443.55 mg and CG: 272.95- 413.57 mg/100 g of seeds), p-cymene (CLG: 181.71-244.17 mg, CG: 369.80- 374.40 mg/100 g of seeds), dehydro-sabina ketone (CLG: 24.60- 25.83 mg, GC: 44.02-50.69 mg/100g of seeds), carvacrol (CLG: 10.32-10.96 mg, CG: 3.91-12.67 mg/100 g of seeds) and longifolene (CLG: 11.90- 16.43 mg, CG: 12.72-19.58 mg/100 g of seeds).Results showed that essential oils exhibit a good activity in each antioxidant system with a special attention for β-carotene bleaching test (IC50: 21 to 27 μg/ml) and reducing power (EC50: 9 to 14 μg/ml).The N. Sativa essential oils exhibited higher antibacterial and antifungal activities varying according to technique extraction and grinding mode used, with a high effectiveness against Gram-positive bacteria with a diameter of inhibition zones growth ranging from 9.5 to 35 mm and MIC and MBC values ranging from (0.042–0.10 mg/ml) to (0.20–0.75 mg/ml), respectively [less ▲]

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See detailComposition and dynamics of the great Phanerozoic Evolutionary Floras
Cleal, Christopher J.; Cascales - Miñana, Borja ULg

in Proceedings of the XXIX Annual Meeting of the Spanish Society of Palaeontology (abstract book) (2013, October)

Detailed reference viewed: 15 (0 ULg)