Carmen Martin

Design methods applied to the selection of a rapid prototyping resource

The article first introduces the problem in question and discusses the interest in implementing a concurrent engineering approach. It focuses on the relevant rapid prototyping techniques likely to be used in order to make the design and production processes more reliable. Next, the article describes in generic terms the advantages of using the QFD method as a decision making tool. The practical case study chosen is related to the selection of a prototyping resource. After identifying the functions to be fulfilled by the rapid prototyping resource, a technology deployment matrix is built and the principles leading to the results are commented upon.

Inequality Indices Based on the Notion of Shannon-Entropy for the Assessments of Industrial Fleets

The state-of-the-art related to reliability, availability and maintainability (RAM), provides indices that allow to effectively measuring different attributes on single complex assets. However, those methodologies usually present limitations when the aim is to analyse grouping maintenance or the remaining useful life in fleets of assets. The purpose of this contribution is to suggest the advantages of measures based on the notion of Shannon entropy, applied to fleet RAM analysis. Particularly, this research presents a derivation from well-known concepts such as the Gini, Hoover, and Theil indices.

Importance of test parameters, specimen type and use configuration on the identification of Sn/Ag solder behaviour laws

Abstract In this paper, solder bump interconnections based on a Tin brazing process are studied under the angle of their capacity to resist to repeated thermomechanical loading. Indeed, understanding and modelling nonlinear behaviour is one of the most important milestones in the process of assessing solder reliability. However, the identification of soldering behavioural laws is highly dependent on the context and in particular on the nature of the specimen, the processes used to manufacture it as well as its utilization. This gave rise to a large number of models for the description of the creep in solder materials. Within this framework, the article aims first at proposing a state of the art on the most relevant models describing the nonlinear time dependent behaviour of this kind of solder alloy and, in particular, the different works that have addressed the modelling of the behaviour of Sn/Ag specimens. Due to the diversity of existing models, a methodology is then proposed to match analytical models and experimental data. It is shown that the results depend on the experimental setup and on the temperature used for the tests. Shear relaxation tests are used to identify primary and secondary creep. The results are discussed with respect to models and range of temperature. Based on the previous developments, an adaptation of the laws found in the literature is proposed to describe the behaviour of a Sn/Ag3.5 wire bond solder used in an IGBT rail traction module. The outcomes are experimentally validated.

Methodological framework for implementation of a prediction reliability model of IGBT power modules used in railway applications

The control of critical electronic components reliability is one of the main issues in railway traction applications. Insulated Gate Bipolar Transistors (IGBT) modules are part of these components. They are subjected to high stresses due to severe conditions of use of the train. The increase of requirements in terms of reliability and safety imposes to be able to assess these dependability measures. This paper introduces a methodological framework for predicting reliability of IGBT based on an innovative and structured Bayesian approach.

Systemic Assessment of Human-Factor-Based Security Impact

The paper deals with the use of a multicriteria approach based on a BOCR (Bonus Opportunity Cost Risk) analysis and the satisficing game theory to allocate a task to an operator from the contextual knowledge of its environment and the risk that may arise with respect to industrial safety. An application is given related to the allocation of tasks in the field of aeronautics maintenance by considering both performance an human factor impact on security.

Reliability Assessment of a Multi-Redundant Repairable Mechatronic System

The reliability modelling of redundant systems is an important step to estimate the ability of a system to meet the required specifications. Markov chains have characteristics making it very simple the graphic representation of this type of model. They however have the disadvantage of being quickly unworkable because of the size of the matrices to be manipulated when systems become complex in terms of number of components or states. This issue, known as of combinatorial explosion is discussed in this chapter. Two methods are proposed. The first one uses the concept of decoupling between phenomena driven by different dynamics. The second is based on a principle of iteration after cutting the model into classes of membership. Both are based on the principles of approximating the exact result by reducing the scale of the problem to be solved. A case study is eventually carried out, dealing with the reliability modelling and assessing of a mechatronic subsystem used for an Unmanned Aerial Vehicle flight control with a triple modular redundancy. Results are discussed.