No abstract

This article deals with the propositon of a new generation of our industrial factories. The integration of the most resulting advanced techniques will lead to a change of paradigm in the definition of new efficient production systems. In this article, we develop the main ideas of the project ARTUR. The core is to build new and executable strategies for embedding both current and new simulation capabilities into factory material processing and product evaluation; thereby creating a human friendly "robotic" factory environment where online simulation can control both process and product performance in real-time.

On-line consolidation process is a promising non-autoclave technique to design large size parts in aeronautical industry. Residual stress growth during the process is locking significantly the process validation. In this paper, we present a multi-scale modeling based on the constrained natural element method (C-NEM) and on the proper orthogonal decomposition method which allows to evaluate residual stress growth. The method allows to take into account the thermomechanical properties evolution of the material during the process, which is a dominating factor in residual stress development.

This communication deals with a comparison between two methods of discretization: the well known finite element method and the natural element method that is a meshless method. An error estimator, based on the nonverification of the constitutive law, is used. This estimation has been applied to two examples: a device with permanent magnets and a variable reluctance machine.

A smooth particle-mesh Ewald algorithm for Stokes suspension simulations: The sedimentation of fibers Abstract. In this work we discuss some unresolved problems related to the numerical modelling of short fiber suspensions. Two types of simple flows are examined. First, we analyze the difficulties encountered in the treatment of steady recirculating flows, where the advection equation governing the evolution of the fiber orientation distribution, or that governing the evolution of its different moments (orientation tensors), is assumed to have a steady solution despite the fact that neither boundary conditions nor initial conditions are known. We pointed out in previous studies the large deviations that result from solving these advection problems using stabilized finite element techniques such as SUPG and discontinuous Galerkin, in comparison with a reference solution that is either known, or computed by imposing its periodicity along the closed streamlines.A similar problematic is found in simple shear flows involving suspensions of fibers with finite aspect ratio. In this case, the existence of a fully developed regime that differs significantly from the solution computed numerically is proved, and a discussion of the stability of the flow is presented.

A mathematical treatment for a heat penetration phenomenon with variable boundary conditions is presented. The system of differential equations for determining the unsteady-state temperature distribution inside a particle was solved by use of spectral methods as a new tool in food process development. A preliminary study was conducted on the use of a mathematical model to predict lethality in a sterilizing process. The model was validated using a calibrated time-temperature integrator (TTI) with immobilized Bacillus stearothermophilus spores, commonly used in TTIs for process validation. A comparison between the experimental data using Bacillus stearothermophilus and the predicted data obtained with the proposed model showed good agreement.

No abstract

Efficient numerical models have been already developed in 2D to take into account the movement of electromagnetic devices with rotating parts in the framework of the Finite Element Method (FEM). When the movement becomes complex it leads to large mesh distortions. A remeshing step is then required which increases the computational complexity and can also lead, in some cases, to numerical ripples on forces and torques due to the field projections between old and new meshes. Moreover, remeshing procedures in 3D remain an open topic. Meshless methods seem an appealing choice for alleviating the mesh constraints. The Natural Element Method (NEM) which, has known a growing interest in the domain of mechanics, allows to proceed in the meshless framework, avoiding one of the main drawbacks related to the vast majority of meshless techniques, as is the imposition of essential boundary conditions. In this paper, a variant of the NEM, known as constrained natural element method (C-NEM) is applied for simulating electromagnetic machines involving rotating parts. A new mixed strategy combining the finite element and the constrained natural element methods is proposed and then tested by using an appropriate error estimator.