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The intrinsic structure of composites can lead to defects decreasing their reliability and their
in-mission security. Numerical simulations aiming to improve and support defect detection are envisaged in this work. More precisely, shearography and thermography as non-destructive detection methods are being modeled here. Two defect types are considered: delamination and porosity.

Detection is investigated with external thermal excitation, leading to thermal and mechanical
analysis in simulations. Firstly, an overview of composites, their defects and non-destructive techniques is addressed. Secondly, prerequisites for simulations like governing equations and assumptions made, the heater characterization, and the numerical scheme used for the transient thermal problem resolution are exposed. Then, defect numerical models are constructed and studied. Delamination and porosity are the two types of defects considered. Numerical models for the delamination covered true delamination and artificial delamination like the physic insert and flat bottom hole models. The porosity model is represented by a few flat bottom holes localized in a small region. Finally, an experimental approach compared with numerical results is used as a validation method.

Different delamination models are developed and they show pretty well concordances between
them, except for the Teflon layer (type of physic insert) model for which the mechanical response
was not expected or at least, suggests a further study to determine its validity. The porosity model showed difficulties in this kind of defect detection. Finally, the experimental approach enabled to see that numerical and experimental results were similar but that some efforts on parameter updating remain to be made. Mainly the characterization of the lamp that irradiates a highly non-homogeneous flux.

Numerical Simulations --- Shearography --- Thermography --- Delamination models --- Porosity models --- Experimental validation --- Ingénierie, informatique & technologie > Ingénierie aérospatiale

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The present final work project has been performed at Sonaca, a Belgian company which is producing aeronautical components. The objective was to study composite leading edge slat designs and more precisely the feasibility of using aluminium honeycomb cores as
energy absorption elements to handle the issues of composites parts submitted to bird impact. After a validation of the numerical simulation on a well known aluminium slat design, two composite designs have been studied. A hybrid design which combines an aluminium slat top skin and a composite rear structure has been found compliant with birdstrike requirements while cutting down the weight of the whole structure by 17.2% and the weight of the slat itself by 27.1% with respect to a reference aluminium slat design. Thereafter, the constitutive model used to represent the crushing behavior of aluminium honeycomb core has been identified using quasi-static crushing experiments before it has been validated under dynamic conditions using an birdstrike experiment carried out on a fixed leading edge. A full composite slat design associated to a fixed leading edge reinforced with aluminium honeycomb core has been proven compliant with birdstrike requirements while cutting down the weight of the whole structure by 17.5% and the weight of the slat itself by 41.7% with respect to a reference aluminium slat design. Key prerequisites for slat design integrating aluminium honeycomb cores such as the absence of localised stiff points and a sufficient stiffness of the part which support the core have been identified. The influence of the some design parameters has finally been assessed to give a first insight of the elements which should be taken into account during sizing of fixed leading edge reinforced with aluminium honeycomb cores.

Impact d'oiseau --- Nid d'abeille aluminium --- Simulations numériques --- Plastique à renfort fibre de carbone --- Birdstrike --- Aluminium honeycomb --- Carbon fibre reinforced polymer --- Numerical simulations --- Ingénierie, informatique & technologie > Ingénierie mécanique

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The investigation of rail vehicle running dynamics plays an important role in the more than 200 year development of railway vehicles and infrastructure. Currently, there are a number of new requirements for rail transport associated with the reduced environmental impact, energy consumption and wear, whilst increasing train speed and passenger comfort. Therefore, the running dynamics of rail vehicles is still a research topic that requires improved simulation tools and experimental procedures. The book focuses on the current research topics in railway vehicles running dynamics. Special attention is given to high-speed railway transport, acoustic and vibrational impact of railway transport to the surroundings, optimization of energy supply systems for railway transport, traction drives optimization and wear of wheels and rails.

Technology: general issues --- History of engineering & technology --- Environmental science, engineering & technology --- wear --- turnout --- rail --- stiffness --- high-speed --- dynamic characteristics --- traction drive system --- direct torque control --- electromechanical coupling modeling --- variable conditions --- rail vehicle --- rail infrastructure --- threshold effect --- dynamics --- numerical simulations --- testing --- optimal controller --- traction drive --- vector control system --- railway noise --- high-speed railways --- environmental impact --- energy saving --- control by forecast --- power limit of consumption --- railway transport infrastructure object --- simulation in the daily cycle --- n/a

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History of engineering & technology --- sidewall quenching --- LES --- premixed methane --- flame–wall interaction --- FGM --- Lewis number --- flame curvature --- iso-scalar non-material surfaces --- turbulent premixed spherical flame --- reaction waves --- turbulent reacting flows --- turbulent consumption velocity --- bending effect --- reaction surface area --- molecular transport --- direct numerical simulations --- turbulent flame --- premixed turbulent combustion --- countergradient transport --- flame surface density --- scalar dissipation rate --- modeling --- large eddy simulation --- confined --- boundary layer flashback --- turbulent combustion --- hydrogen --- autoignition modelling --- reduced chemical kinetics --- gasoline surrogates --- engine knock --- spray combustion --- evaporative cooling --- flame surface wrinkling modeling --- thickened flame --- flamelet generated manifold --- n/a --- flame-wall interaction

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sidewall quenching --- LES --- premixed methane --- flame–wall interaction --- FGM --- Lewis number --- flame curvature --- iso-scalar non-material surfaces --- turbulent premixed spherical flame --- reaction waves --- turbulent reacting flows --- turbulent consumption velocity --- bending effect --- reaction surface area --- molecular transport --- direct numerical simulations --- turbulent flame --- premixed turbulent combustion --- countergradient transport --- flame surface density --- scalar dissipation rate --- modeling --- large eddy simulation --- confined --- boundary layer flashback --- turbulent combustion --- hydrogen --- autoignition modelling --- reduced chemical kinetics --- gasoline surrogates --- engine knock --- spray combustion --- evaporative cooling --- flame surface wrinkling modeling --- thickened flame --- flamelet generated manifold --- n/a --- flame-wall interaction