No abstract

The paper deals with the characterisation and modeling of the mechanical stressdependency of magnetic losses along two orthogonal directions in non-oriented electrical steels. Significant anisotropy effects are highlighted. Using the three-term loss separation approach, the different loss components are computed at each stress level for a wide range of frequency. Stress dependence of the core losses can be described in terms of the hysteresis and excess loss components, classical losses being assumed to be constant as a function of stress. Variations of the model coefficients with stress along the two principal directions are discussed. Such a model can be used for computing the losses in finite element analysis of rotating electrical machines or T-joint of transformers.

Abstract. In the automotive industry, the integration of thermoplastic composite components represents a high-potential solution to the mass reduction challenge. In this study, a woven glassfibre-reinforced composite with a polyamide 6,6 matrix is considered for the purpose of being integrated into automotive parts. Tension-tension fatigue tests were conducted on [(0/90) 3 ] openhole samples. These tests were instrumented with non-destructive techniques, namely acoustic emission and infrared thermography. Acoustic emission results showed fibre-matrix debonding and fibre breakages in open-hole samples, located around the hole. Furthermore, 3-point bending fatigue tests were performed on "omega" mini-structures. A semi-empirical model was used in order to predict the fatigue lives of both open-hole coupons and automotive mini-structures. Predictions of the model for open-holes samples underestimate experimental fatigue lives. Nevertheless, the semiempirical model showed good results for the fatigue life prediction of composite mini-structures.

L’assemblage par clouage de deux tôles d’acier est présenté au moyen d’une approche numérique et expérimentale. Un modèle de l’étape d’assemblage est réalisé et confronté aux données expérimentales pour différents paramétrages de la machine. La simulation est ensuite utilisée pour l’évaluation des phénomènes locaux observés au sein des tôles, tels que les modes de rupture et les élévations de température.