Ijodir 2008

Critical scenarios for dynamic systems reliability

Last Updated on Monday, 20 September 2010 11:09

 

Authors: Nabil SADOU, Hamid DEMMOU

Institutions: LAAS-CNRS, University of Toulouse

Abstract: This paper deals with reliability of dynamic systems. It is addressed by generating critical scenarios. This paper proposes a definition of the concepts of minimality and completeness, related to the notion of scenario. These two concepts guarantee the pertinence of scenarios. In Petri net model, a scenario is defined as a partial order between events leading from one partial state to another one. We use linear logic as a new representation of Petri net model. The definition of minimality and completeness is based on this new representation.

Keywords: Temporal Petri nets, linear logic, scenario, minimality, completeness

 

 

Thermal reliability of Power Modules Using Probabilistic Approaches

Authors: A. Micol, C. Martin, O. Dalverny, M. Mermet-Guyennet, M. Karama

Institutions: LGP-ENIT, Power Electronics Associated Research Laboratory (PEARL)

Abstract: The weak point for the standard power IGBT modules in terms of reliability is thermal fatigue in solder joints due to the thermal stress induced by constitutive materials with different coefficients of thermal expansion (CTE). So far, many researches are aimed at defining accurate finite element simulation with constitutive equations of materials behaviour and fatigue failure relation connecting the inelastic strain and the number of cycles before failure. The aim of this paper is to estimate the probability of failure of power module with the structural reliability methods which taking into account the scatter of input data. Thus thermal material and loading variables are considered as random variables and a thermal failure mode is modelled with the called limit state function. The sensitivities of the probability of failure with respect to the mean and the standard deviation for each random variable have been evaluated.

Keywords:  IGBT, power module, reliability, FORM, bump, Sn/Ag solder.

 

Holographic vibration measurement and numerical modelling of immersed structures

Last Updated on Monday, 20 September 2010 15:29

 

Authors: Abderahman Makhloufi, Dan Borza, Ioan Stoian, Abdelkhalak Elhami, Ioana Nistea, Mihaela Gordan

Institutions: INSA Rouen, SC IPA SA, Université Technique de Cluj-Napoca

Abstract: Video systems used in the inspection of submerged dam walls use digital cameras. This allows flexibility and operability, while providing a high level of stability and positioning accuracy. In presence of dynamic excitations, the mechanical components of the inspection system are submitted to vibrations which may degrade its over-all performance. When a mechanical structure is immersed, its eigenfrequencies and eigenmodes are different from those occurring in air. This paper presents a study concerning a numerical modelling of immersed structures and its experimental validation by a full-field, non-contact measurement technique. The hydroelastic modelling of the structure is performed by finite elements and the experimental measurements by speckle interferometry setup. The experimental results are correlated with the numerical ones, and the numerical model is updated.

Keywords: immersion, vibration, numerical model, speckle interferometry

 

 

Steering numerical simulations by means of requirement engineering

Last Updated on Monday, 20 September 2010 15:29

 

Authors: Maher AIDI, Rémy Gautier, Michel Tollenaere, Franck Pourroy, Aref Maalej

Institutions: LASEM ENIS, INPG, G-SCOP, Arts et Metiers ParisTech Paris, LCPI, (France)

Abstract: The control of the numerical simulations in product design constitutes a key factor of industrial companies’ competitiveness. Indeed, it contributes at the same time to the quality of the products and to the shortening of the development cycles. Also, the design solution based on the requirement engineering allows each product life cycle actors, with the progression of their simulation activity, to have a coherent vision of the customer need. This functional approach underlines attention to validate the customer’s requirement in simulation according the product evolution and maturity, also, to guarantee the conformity of specifications. This paper presents a systematic method to support the simulation activities during design based on the requirements engineering. In addition, this methodological contribution gives rise to some opportunities for improving simulation data management and reusing of simulation knowledge.

Keywords: as maximum number of relevant keywords should be included, both in French and in English.

 

 

From concurrent engineering to collaborative learning of design

Last Updated on Thursday, 04 April 2013 11:45

Authors: Nicolas Maranzana, Nathalie Gartiser, Emmanuel Caillaud

Institution: INSA Strasbourg, Université de Strasbourg, LGECO (France)

Abstract: In the hostile and competitive environment we live in, complexification of products and systems, as well as the necessity to innovate drive the companies to work together more and more. Literature dealing about themes of group work abounds ; terms are however defined in a blurred and even contradictory way depending on the authors. Our paper aims at contributing to this clarification. Therefore, having defined the terms of communication, coordination, cooperation and collaboration, we shall more particularly analyse the design activity in a group and shall characterize distributed design and collaborative design. By using this characterization, we shall show the link with the learning of design in network. We will conclude on two collaboration levels between partners in an innovation context, namely : design together and learn together how to design.

keywords : concurrent engineering, co-design, collaborative design, distributed design, learning, inter-companies

Ijodir 2008 / Vol 4 n°1 - From concurrent engineering to collaborative learning of design
   2010-09-17  0 B  1319