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Peer Reviewed
See detailMechanical behaviour model of an unsaturated sandy silt
Charlier, Robert ULg; Li, X. L.; Bolle, Albert ULg et al

in Proc. of the XIVth Int. Conf. on Soil Mechanics and Foundation Engineering (1997, September)

Detailed reference viewed: 30 (2 ULg)
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See detailMechanical behaviour of chalk reservoir: Numerical modelling of water sensitivity and time dependence effects
Collin, Frédéric ULg; Cui, Yu Jun; Schroeder, Christian ULg et al

Conference (2003)

The paper proposes two numerical models ot the mechanical behaviour of chalk. First, an elasto-plastic constitutive law reproduces the different plastic mechanisms of the chalk and the influence of pore ... [more ▼]

The paper proposes two numerical models ot the mechanical behaviour of chalk. First, an elasto-plastic constitutive law reproduces the different plastic mechanisms of the chalk and the influence of pore fluids by introducing the concept of suction. Secondly, a model able to reproduce time dependence behaviour. Eventually, the paper gives a simulation of an academic reservoir during depletion and waterflooding phase. [less ▲]

Detailed reference viewed: 35 (3 ULg)
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See detailMechanical behaviour of chalk reservoirs: numerical modelling of water sensitivity effects
Collin, Frédéric ULg; Cui, Yu Jun; Schroeder, Christian ULg et al

Conference (2003)

Chalk is the constituent material of numerous oil reservoirs in North Sea. The mechanical behaviour of a saturated chalk has been largely studied. However, different aspects of its behaviour are not yet ... [more ▼]

Chalk is the constituent material of numerous oil reservoirs in North Sea. The mechanical behaviour of a saturated chalk has been largely studied. However, different aspects of its behaviour are not yet well understood: material characteristics depend on the saturating fluids and chalk response is time-dependent. This paper proposes the PASACHALK numerical model: an elasto-plastic constitutive law is presented, which reproduces the different plastic mechanisms of the chalk (pore collapse and shear failure) and the influence of pore fluids. The water sensitivity of this soft rock is explained by the existence of suction effects in chalk. Finally, a simulation of a hypothetical reservoir is proposed to show the response of the elasto-plastic model during depletion phase and water injection phase. [less ▲]

Detailed reference viewed: 47 (3 ULg)
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Peer Reviewed
See detailMechanical behaviour of Lixhe chalk partly saturated by oil and water: experiment and modelling
Collin, Frédéric ULg; Cui, Yu Jun; Schroeder, Christian ULg et al

in International Journal for Numerical and Analytical Methods in Geomechanics (2002), 26(9), 897-924

Two or more different fluids generally saturate chalk in oil reservoir, and therefore its behaviour can be very complicated. In this paper, a constitutive law is proposed for modelling the mechanical ... [more ▼]

Two or more different fluids generally saturate chalk in oil reservoir, and therefore its behaviour can be very complicated. In this paper, a constitutive law is proposed for modelling the mechanical behaviour of a chalk saturated by two non-miscible fluids, water and oil. The effects of the capillary pressure or suction are taken into account. They are considered as an independent variable, as in the Barcelona's basic model developed for unsaturated soils. On the other hand, internal friction and pore collapse are modelled as independent mechanisms. The determination of the parameters is based on triaxial and oedometer tests. Finally, in order to validate the model, predictions are compared with experimental results of water-flooding test. Copyright (C) 2002 John Wiley Sons, Ltd. [less ▲]

Detailed reference viewed: 74 (12 ULg)
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Peer Reviewed
See detailMechanical behaviour of tape springs used in the deployment of reflectors around a solar panel
Dewalque, Florence ULg; Collette, Jean-Paul; Bruls, Olivier ULg

in Acta Astronautica (2016), 123

In order to increase the production of power on small satellites, solar panels are commonly deployed and, in some cases, reflectors are added to improve the concentration factor on solar cells. In this ... [more ▼]

In order to increase the production of power on small satellites, solar panels are commonly deployed and, in some cases, reflectors are added to improve the concentration factor on solar cells. In this work, reflectors are deployed by the means of compliant mechanisms known as tape springs. Their attractive characteristics are, among others, their passive behaviour, their self-locking capacity, their elastic deformations and their robustness. However, their mechanical behaviour is highly nonlinear and requires thorough analyses in order to develop predictive numerical models. It is shown here through parametric studies that the nonlinear behaviour of a tape spring is mainly governed by its geometry. Thus, for each specific application, its dimensions can be determined in order to minimise two critical features: the maximum stress affecting the structure and the maximum motion amplitude during deployment. In this paper, an optimisation procedure is proposed to meet these requirements. [less ▲]

Detailed reference viewed: 45 (17 ULg)
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See detailMechanical behaviour of tape springs used in the deployment of reflectors around a solar panel
Dewalque, Florence ULg; Collette, Jean-Paul; Bruls, Olivier ULg

in Proceedings of the 6th International Conference on Mechanics and Materials in Design (M2D) (2015)

In order to increase the production of power on small satellites, large solar panels are commonly deployed and, in some cases, reflectors are added to improve the concentration factor on solar cells. In ... [more ▼]

In order to increase the production of power on small satellites, large solar panels are commonly deployed and, in some cases, reflectors are added to improve the concentration factor on solar cells. In this work, reflectors are deployed by the means of compliant mechanisms known as tape springs. Their attractive characteristics are, among others, their passive behaviour, their self-locking capacity, their elastic deformations and their robustness. It is shown here through parametric studies that the behaviour of a tape spring is mainly governed by its geometry. Thus, for each specific application, its dimensions must be determined in order to minimise two critical features: the maximum stresses affecting the structure and the maximum amplitudes of motion during deployment. In this paper, an optimisation procedure is proposed to meet these requirements. [less ▲]

Detailed reference viewed: 61 (8 ULg)
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Peer Reviewed
See detailMechanical Buckling of Composite Panels with/without Cutouts
Pascan, Oana; Zhang, Weihong; Ponthot, Jean-Philippe ULg

in International Journal of Plant Engineering and Management (2012), 17(2), 65-76

A simpli ed analytical solution suitable for simple stacking sequences was developed using the Euler buckling theory, the structure's equations of equilibrium and laminate panel mathematical formulation ... [more ▼]

A simpli ed analytical solution suitable for simple stacking sequences was developed using the Euler buckling theory, the structure's equations of equilibrium and laminate panel mathematical formulation. Comparing these results with numerical results reveals the ac- curacy of the method and even more, allows us to validate the numerical analysis. Therefore, two important results are obtained : a simpli ed analytical solution for the buckling problem and vali- dation of the numerical results. Another important and novel nding is related to the in uence of the angle ply orientation and of the cutouts, on the buckling load. Under symmetrical boundary conditions and loading case, rectangular panels with elliptical cutouts, give better results for 90 oriented plies than for 0 oriented ones. With a compression load applied in the X direction, and with material properties 10 times better in X direction than in Y direction, the best results are obtained when the load is aligned with the Y direction associated to the material reference frame. Moreover, panels with cutouts seem to behave better than panels without cutouts under certain ply orientation angles. [less ▲]

Detailed reference viewed: 25 (0 ULg)
Peer Reviewed
See detailMechanical characterization of porous structures by the combined use of micro-CT and in-situ loading
Kerckhofs, Greet ULg; Schrooten, Jan; Elicegui, Laida et al

Conference (2008)

Detailed reference viewed: 15 (2 ULg)
Peer Reviewed
See detailMechanical characterization of porous structures by the combined use of micro-CT and in-situ loading
Kerckhofs, Greet ULg; Schrooten, Jan; Elicegui, Laida et al

in Proceedings book WCNDT 2008 (2008)

Detailed reference viewed: 14 (4 ULg)
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Peer Reviewed
See detailMechanical comparison of eight vertical jump exercises
Jidovtseff, Boris ULg; Cronin, John; Harris, Nigel et al

in Computer Methods in Biomechanics & Biomedical Engineering (2010, September), 13(S1), 77-78

Detailed reference viewed: 139 (18 ULg)
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Peer Reviewed
See detailMechanical constitutive framework for thermal effects on unsaturated soils.
François, Bertrand ULg; Nuth, Mathieu; Laloui, Lyesse

in Proceeding of the 10th Int. Symp. on Numerical Models in Geomechanics, NUMOG X (2007)

Research interest in the thermo-mechanical behaviour of unsaturated soils is growing as a result of an increasing number of geomechanical problems involving both thermal and suction effects. The ... [more ▼]

Research interest in the thermo-mechanical behaviour of unsaturated soils is growing as a result of an increasing number of geomechanical problems involving both thermal and suction effects. The underground waste disposal is one such critical problem. Until now, these two environmental loadings have often been considered independently. This paper proposes a new unified thermo-mechanical framework for unsaturated soils based on thermo-hydro-mechanical (THM) experimental evidence on cohesive soils. The Bishop effective stress framework is adopted to represent the stress state in the soil in a unified fashion. This constitutive context based on the evolution of two key parameters (the preconsolidation pressure and the suction air-entry value) makes it possible to represent the main features of the thermo-mechanical behaviour of unsaturated soils. [less ▲]

Detailed reference viewed: 30 (1 ULg)
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Peer Reviewed
See detailThe mechanical control of peri-implant bone remodeling investigated by in vivo imaging and in silico modeling
Li, Zihui; Betts, Duncan; Kuhn, Gisela et al

Conference (2016, July)

Detailed reference viewed: 17 (1 ULg)
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See detailMechanical design, control and optimization of a hybrid solar microgrid for rural electrification and heat supply in sub-Saharan Africa
Altés Buch, Queralt ULg

Master's dissertation (2016)

This thesis aims at developing, optimizing and controling a hybrid solar microgrid for rural electrification and heat supply in sub-Saharan Africa. The considered system includes PV, Parabolic Trough ... [more ▼]

This thesis aims at developing, optimizing and controling a hybrid solar microgrid for rural electrification and heat supply in sub-Saharan Africa. The considered system includes PV, Parabolic Trough Collectors, Organic Rankine Cycle and LPG generator, as well as chemical battery storage and thermal energy storage. The work focuses on multiple aspects of the ongoing development of solar hybrid microgrids for the rural electrification of remote areas in Lesotho. These aspects range from very specific improvements (the mechanical design of a high expansion ratio expander) to the more global evaluation of their impact once included into a complex micro-grid system. Special attention has also been paid to the links between thermal and electrical demands. The main contributions of this thesis are: – The mechanical design of a high expansion ratio scroll expander, involving drawing, machining and assembly of the parts. – The detailed model of an organic Rankine cycle with the purpose of evaluating the improvement brought by the high expansion ratio scroll expander and mapping the ORC performance. – A building model developed to predict the thermal loads of a health clinic in rural communities of Lesotho. The developed lumped-parameter model can be used for various building typologies and communities. The model is designed to be as generic and simple as possible, and contrasts with the data-intensive models generally proposed in the literature. – The gathering of monitoring and weather data relative to a health clinic in Lesotho, and their use for the calibration of the building model. – A microgrid model built by interconnecting all of its subcomponent models. A rule- based control strategy is developed, accounting for interactions between thermal and electrical loads, and dispatching heat and power flows of each component in order to cover the demand while minimizing the fuel consumption. – A particle-swarm optimization model used to optimize the microgrid under different cost assumptions and control strategies. The above models prove that the system performs better with the developed high expansion ratio expander. The maximum output power of the ORC is increased by 33%, and the fuel consumption of the microgrid is reduced by 25%. For the studied community of Ha Nkau in Lesotho, the determined optimal system infrastructure is composed of PV (65 kW) and batteries (259 kWh) only, and the optimum control strategy achieves a levelized cost of electricity of 0.202 USD/kWh. Fuel consumption is mainly due to the burner, which supplies all the thermal load because no other heating system is selected by the optimization. [less ▲]

Detailed reference viewed: 21 (2 ULg)
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See detailThe mechanical effects of short-circuit currents in open air substations (Part II)
Lilien, Jean-Louis ULg; Declercq, Guy; El adnani, Mustapha et al

Book published by CIGRE (2002)

This book is a companion book of teh CIGRE brochure N° 105 (1996) on the same subject. It evaluates short-circuit mechanical effects and corresponding design loads in substation. It includes both rigid ... [more ▼]

This book is a companion book of teh CIGRE brochure N° 105 (1996) on the same subject. It evaluates short-circuit mechanical effects and corresponding design loads in substation. It includes both rigid and flexible bus-bars, Ac and DC network. It is divided in two volumes, the second one is giving numerous data and tests results of short-circuit. The first volume is detailing methods (simplified, medium and advanced ) to solve these problems. [less ▲]

Detailed reference viewed: 436 (3 ULg)
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See detailThe mechanical effects of short-circuit currents in open air substations (Rigid and Flexible bus-bars)
Lilien, Jean-Louis ULg; declercq, Guy; El Adnani, Mustapha et al

Book published by CIGRE (1996)

A full revision of the 1987 version of the same brochure,including new development on bundle conductors and a full data base of tests.It includes short-circuit mechanical effects in substations for AC and ... [more ▼]

A full revision of the 1987 version of the same brochure,including new development on bundle conductors and a full data base of tests.It includes short-circuit mechanical effects in substations for AC and DC structures, for rigid and flexible busbars. [less ▲]

Detailed reference viewed: 353 (1 ULg)
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See detailThe mechanical effects of short-circuit currents in open air substations.
Nartowski, Zbigniew; Adami, H.; Ford, Gary et al

Book published by CIGRE (1987)

SHort-circuit mechanical effects in substation is investigated by tests and simulations. Simplified equations are deduced to prepare standardisation of a procedure forthe design of substation against ... [more ▼]

SHort-circuit mechanical effects in substation is investigated by tests and simulations. Simplified equations are deduced to prepare standardisation of a procedure forthe design of substation against short-circuit mechanicle effects. [less ▲]

Detailed reference viewed: 729 (4 ULg)
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Peer Reviewed
See detailThe mechanical effects of short-circuit currents in substations with flexible conductors. Numerical Methods - Computer Approach.
Lehmann, Werner; Lilien, Jean-Louis ULg; Orkisz, J.

in Proceedings of CIGRE 1982 (1982, September 01)

A review of the application of advanced computer methods to the evaluation of the mecanical effects caused by the electromagnétic forces associated with short-circuit currents.

Detailed reference viewed: 91 (2 ULg)
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Peer Reviewed
See detailMechanical effects of short-circuit currents in substations with strain bus systems. Medium complexity calculation methods.
Gauffin, Louis; Lilien, Jean-Louis ULg

in Proceedings of the CIGRE Symposium 06-85 (1985)

This paper details various methods (medium complexity) for calculation of conductor tensions and displacements of substation under short-circuit loading.

Detailed reference viewed: 91 (2 ULg)
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See detailMechanical effects of short-circuit currents in substations with strain bus systems. Parameter Analysis and simple method of calculation.
Lilien, Jean-Louis ULg; Brokamp, Luc

in Proceedings of the CIGRE Symposium 06-85 (1985, June)

SImple methods to evaluate short-circuit mechanical effects in substation.

Detailed reference viewed: 89 (0 ULg)