In order to analyze the formability of steels in sheet metal forming, a ductility loss criterion is coupled with a multiscale model. The behavior at the mesoscopic (grain) scale is modeled by a large strain micromechanical constitutive law, which is then used in a self-consistent scale transition scheme. Hardening at the slip system level is taken ...
Différentes approches de modélisations ont été proposées pour prédire les phénomènes de localisation lors d’opérations de mise en forme de tôles métalliques par emboutissage. Des exemples de ces approches sont le principe de force maximum, les critères à deux zones et les analyses de bifurcation ou de stabilité. En l’absence de consensus relatif à ...
Analysis of the evolution in solar heated drying kilns in recent decades shows that there have been a series of modifications to optimize their thermal and drying efficiency. Using an analysis method based on product design, we report on existing solar timber kilns. The dryers and their component units are studied, developments are noted, focusing ...
In this paper, a hybrid analytical-numerical approach is performed for the orthogonal cutting process. The modelling of the thermomechanical material flow in the primary shear zone, the tool-chip contact length and the sliding-sticking zones are obtained from an analytical approach. In addition, the Finite Element method is used to solve the non li...
Fatigue tests were performed on ferritic bainitic steel notched specimens (Kt = 2.5) under load controlled constant amplitude loading. These tests show that under constant amplitude tension compression loading, periodical overloads application have a detrimental effect on the fatigue crack initiation strength for fully reversed load ratio (R σ = — ...
The data available in the literature concerning wood cutting forces permit to build models or to simulate the main wood machining processes (milling, sawing, peeling etc.). This approach contributes to a better understanding of formation of wood surfaces and chips and the data may be helpful to optimize cutting geometry, reduce tool wear, improve t...
We present a mathematical method for identifying, separating and quantifying the 3D significant distortions. Measurement of a gas quenched C-ring type sample is performed by a Coordinate Measuring Machine (CMM). Quenching simulation is done with the commercial software Forge 2008 TTT®. After comparisons, we notice that the distortions and their ten...
Numerical modelling of non-Newtonian flows usually involves the coupling between equations of motion characterized by an elliptic character, and the fluid constitutive equation, which defines an advection problem linked to the fluid history. There are different numerical techniques to treat the hyperbolic advection equations. In non-recirculating f...
Arts et Métiers ParisTech, invitation en tant que professeur invité de Paul C. Paris au LAMEFIP / Crack stability is discussed as affected by their presence in statically-indeterminate beams, frames, rings, etc. loaded into the plastic range. The stability of a crack in a section, which has become plastic, is analyzed with the remainder of the stru...
The design activity is the transformation of functional requirements into design parameters. This article presents a structuring method for the design problem exploiting existent and mastered knowledge. The proposed energy analysis leads to the structural definition of the product and the definition of a basis of functions and components. This appr...
