WEMESURF course, 21-25 June 2010, Paris
Course lectures and plenary lectures
Course "Rheology", G. Cailletaud
Abstract
This course provides a description of non linear constitutive equations valid to simulate plastic and viscous behaviour. Rheological models allow to reveal the true nature of the various equations in onedimensional loading cases. Plasticity criteria are either purely deviatoric or depend on hydrostatic pressure. 3D relations needed to implement incremental algorithms in computer codes are exhibited..
Course "Finite Element Method", S. El-Arem
Abstract
- Many physical phenomena in engineering and science can be described in terms of partial differential equations (PDE).
- In general, solving these equations by classical analytical methods for arbitrary shapes is almost impossible.
- The finite element method (FEM) is a numerical approach by which these PDE can be solved approximately.
- The FEM is a function/basis-based approach to solve PDE.
- FE are widely used in diverse fields to solve static and dynamic problems -- Solid or fluid mechanics, electromagnetics, biomechanics, etc.
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Course "Contact mechanics: basics" G. Cailletaud ,
S. Basseville ,
V.A. Yastrebov
Abstract
This course provides an overview of classical case studies dealing with contact problems. It includes general definition and a series of analytical or semi-analytical stress states, depending on contact geometry and material properties..
Course "Experimental approaches to contact mechanics", J. Savkova ,
H. Proudhon
Abstract | |||
| This course provides an overview of experimental methods within contact mechanics-tribology tests, scratch test and instrumented indentation test. It deals with the associated phenomena of contact, adhesion, friction, hardness and wear from one consistent viewpoint. The history, basic theories and of each method are described. | 
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Plenary lecture "Using X-ray microtomography to probe microstructure and damage of structural materials", H. Proudhon
download presentation slides or download handouts in pdf
Abstract | |||
| With the arrival of 3rd generation synchrotron 10 years ago and the subsequent adances in X-ray lab sources, micro-tomography has become a key technique to look into structural materials and understand how they deform and fail. This talk will review recent progress of the technique, looking at tomography using either Synchrotron radiation or an X-ray lab source. | 
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Course "Contact mechanics: damage", E. Héripré ,
L. Sun ,
J. Durand ,
S. Dubouski
download presentation slides or download handouts in pdf
Abstract
The consequences of contact on material damage is introduced. Depending on the loading conditions (e.g. pressure and sliding amplitude) of the components in contact, different kinds of events could appear at the surface of the material such as wear and crack nucleation and propagation. These two kinds of damage will be discussed and the effect of material and surface roughness on the results will be presented as well..
Plenary lecture "A Socratic approach to cold spray of wear resistant coatings"
M. Jeandin
Abstract
The Vulgate of cold spray is not yet well known even though some people can claim for this sometimes, which, however, results in generally held concepts only. Further approaches to cold spray therefore seem to be required. Among them, this presentation will show a Socratic approach, which means to feature what one does not know about the process. This approach results from the famous statement by Socrates which said that the essential in life is "To know what one does not know". It was thus expected to give impetus to R&D in the unknown. When applied to cold spray, 3 major levels of discussion were involved in this approach on which this presentation will elaborate: i.e. that of particles and splats, that of particle-to-coating simulation and that of coating properties. In the final part of the seminar, recent applications to wear-resistant coatings are given and discussed in the light of the previously-described multi-scale and Socratic approach to cold spray..
Course "Computational contact mechanics", V.A. Yastrebov
Abstract
Finite element method (FEM) is well adapted and widely used in continuum mechanics. But when continuum mechanics turns out non-continuum, i.e. one faces with the necessity to solve a problem of interaction of several continuum solids, the FEM requires special approaches and techniques, which will be discussed here. The principle methods of the optimization theory will be discussed in the context of the contact problem as well as other associated aspects such as contact detection, master-slave discretization, and others.
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Plenary lecture "Fatigue and wear prediction in blade-disc fixings of aero-engines"
T. Dick ,
E. Héripré
Abstract
irst of all the blade-disc fixing and it's damage modes are explained. Subsequently an anatomy of the fixing and the countermeasures against damage are considered. Then some elements of a finite element modelling approach are introduced: Material models of base material (Ti6Al4V) and coating (CuNiIn), that account for cyclic plasticity Residual stress fields, introduced by shot peening For high cycle fatigue prediction the Dang Van parameter is used- To take contact geometry change by wear into account, a wear criteria and a mesh updating routine are used
- Finally, computations of a blade-disc fixing, applying some of the mentioned modelling elements, are discussed and a sketch of the subsequent work is given.