Pierre Beaurepaire

Medical Image Processing and Numerical Simulation for Digital Hepatic Parenchymal Blood Flow

This paper deals with the personalized simulation of blood flow within the liver parenchyma, by considering a complete pipeline of medical image segmentation, organ volume reconstruction, and numerical simulation of blood diffusion. To do so, we employ model-based segmentation algorithms developed with ITK/VTK librairies, CATIA software for volumetric reconstructions based on NURBS and Abaqus solution for adapted simulation of Darcy’s law. After presenting experimental results of each step, we explore scientific and technical bottlenecks so that a valid digital hepatic blood flow phantom may be developed in our future research, in direct relation with current open challenges in this domain.

ON THE CONSIDERATION OF UNCERTAINTY IN DESIGN: OPTIMIZATION – RELIABILITY – ROBUSTNESS

Structural designs aspire to ensure the functionality of a system respecting specific requirements defined by engineers. Structural optimization techniques are widely used to optimize the system performances while garanteeing that specific requirements are fulfilled. However, it is worth remembering that uncertainties might affect all design quantities which can make the design problem much more arduous to solve. This paper aims to discuss the formulation of design problems under uncertainty. Several strategies might be identified when considering uncertainties in the objective and/or constraint functions. Moreover, this paper aspires to clarify the notions of robustness and reliability. After a presentation of each formulation, an academic example illustrates the different strategies and shows the main differences between results of each one. Thus, the choice of the formulation should be viewed as a crucial step of design procedure. N. Lelièvre, P. Beaurepaire, C. Mattrand, N. Gayton and A. Otsmane

TOLERANCE ANALYSIS OF A WIPING SYSTEM USING THE PROBABILISTIC APPROACH

A method for tolerance analysis using the probabilistic approach in described in this manuscript. It is applied with success to an industrial problem. The distributions of the random variables are identified using measurements performed on parts collected from the production lines. Finite element analyses are used to model the mechanical behavior and meta-models are subsequently calibrated to reduce the numerical efforts. A reliability analysis is performed in order to compute the defect probability and estimate the quality of the products.