13 research outputs found
Recent Development of MESSINE, a 3D Eddy Current Model
In the 1996 QNDE Conference, we presented a parametric forward model [1], which has been recently named MESSINE (Model for Electromagnetic Simplified Simulation In Nondestructive Evaluation), to predict eddy current signal. The proposed model first discretizes the eddy current distribution into current loops. A parametric description of the shape of these loops is given according to the observation of the results obtained with a three-dimensional finite element code which provides a realistic distribution of the induced currents. The loops’ inductances and resistances are then calculated. By considering the system constituted of the coil and the current loops as a « multi-transformer», their current intensity is determined. The impedance change, which is the component of the eddy current signal, can then be deduced. The model was validated in the case of axisymmetric configurations. Comparisons with both analytical (Dodd and Deeds [2]) and numerical models showed very good agreements. Then the proposed model was applied to three-dimensional configurations. Impedance changes of a coil along rectangular through-wall slot were calculated. Comparisons with experimental results show a fairly good agreement for the impedance change phases, but a poorer one for the impedance change amplitudes. Investigations were made to improve the parametric description of the current loop deformation. One of the solutions to improve the parametric description is presented here
Messine, an Eddy Current Parametric Model for Flaw Characterization
The MESSINE code (Model for Electromagnetic Simplified Simulation In Nondestructive Evaluation) has been developed at CEA/CEREM in order to characterize flaws in steam generator tubes. No analytical or numerical models, that are well adapted to this problem, have been found in the literature. Constructing a forward model by solving Maxwell’s equations seems rather difficult and numerical models (e.g. finite element approach) are not convenient, due to their long computation time. Thus, a new simplified parametric forward model has been constructed using the following three axes: • 2D defect-free configurations for studying the detection capabilities, • 2D and 3D configurations with defects to obtain signal expertise, • defect characterization i.e., eddy current signal inversion.</p
An optimization method fitted for model inversion in non destructive control by eddy currents
An hybrid method combining two algorithms is proposed for the global
optimization of inverted pattern functions encountered in non destructive control by eddy
currents. This method performs first the exploration with a Genetic Algorithm, allowing to
localize a "promising area" . Then the search is intensified inside that area, through a Nelder-Mead Simplex Search
An Eddy Current Model Based on Parametric Description of Induced Current Loops
Our objective is to design a “forward model” for steam generator tube flaw characterization, using eddy current technique. An investigation of the existing forward models was made.</p
Recent Development of MESSINE, a 3D Eddy Current Model
In the 1996 QNDE Conference, we presented a parametric forward model [1], which has been recently named MESSINE (Model for Electromagnetic Simplified Simulation In Nondestructive Evaluation), to predict eddy current signal. The proposed model first discretizes the eddy current distribution into current loops. A parametric description of the shape of these loops is given according to the observation of the results obtained with a three-dimensional finite element code which provides a realistic distribution of the induced currents. The loops’ inductances and resistances are then calculated. By considering the system constituted of the coil and the current loops as a « multi-transformer», their current intensity is determined. The impedance change, which is the component of the eddy current signal, can then be deduced. The model was validated in the case of axisymmetric configurations. Comparisons with both analytical (Dodd and Deeds [2]) and numerical models showed very good agreements. Then the proposed model was applied to three-dimensional configurations. Impedance changes of a coil along rectangular through-wall slot were calculated. Comparisons with experimental results show a fairly good agreement for the impedance change phases, but a poorer one for the impedance change amplitudes. Investigations were made to improve the parametric description of the current loop deformation. One of the solutions to improve the parametric description is presented here.</p
Fictitious electric conductivity modelling of eddy current evaluation of magnetic materials
The INTAQT project: stakeholders’ opinions on future multicriteria scoring tools for animal products
Agri-food chain actors (AFAs) lack reliable information to meet consumer expectations in relation to multiple facets of intrinsic quality of chicken meat, beef, and dairy products from the various European livestock systems. One of the challenges of the INTAQT project is to build, with AFAs, multi-criteria scoring tools related to products global quality. This tool should combine safety, sensory, and nutritional results obtained during the project-based on collection of poultry/beef/dairy samples and possibly other quality criteria. Multi-actor participatory approach was applied to present and discuss the concept of a multicriteria scoring tool, collecting opinions, fears, and expectations on this tool. On a consumer side, it was felt that such a multi-criteria score placed on products could be a clear and simple representation of a complex reality. However, some disadvantages were expressed about its reliability or implementation. For their part, AFAs had varying opinions on the tool’s target, mainly about its possible use as an internal tool or for consumer information, with different pros and cons expressed on both aims. Fears dealt with the building of the tool, and its relevance, representativeness, practical use, and the potential dangers, especially if safety aspects were included. However, both consumers and AFAs agree on the need to include in this tool extrinsic criteria such as farming system sustainability and animal welfare
The INTAQT project: stakeholders’ perceptions and points of view on products quality
The INTAQT project aims to characterize the links between husbandry systems and the quality of poultry meat, beef and dairy products after consulting at national and Europea levels the actors of each sector on their expectations. The first step was to identify their perceptions and points of view in terms of product quality and this communication focuses on results obtained with producers, processors, retailers and some representatives of citizens’ associations. In addition to the intrinsic quality criteria already foreseen in the project (health, nutrition, organoleptic), stakeholders spontaneously expressed the importance of considering extrinsic criteria related to sustainability (animal welfare, environment, socio-economic aspects) as well as technological quality. The other criteria were mentioned in a variable way depending on the type of stakeholder, the country and the sector concerned. These results are consistent with consumers’ views and they have been taken into account to include other quality criteria in the project
The INTAQT project: stakeholders’ expectations on husbandry systems and innovative practices
The INTAQT project aims to establish the relationship between intrinsic and extrinsic quality criteria of animal products and European husbandry systems. Another aim is to evaluate the impact of innovative husbandry practices on the quality of the products. In order to determine, which husbandry systems and practices the project should study, a European-wide stakeholder consultation of the chicken, beef and dairy value chains was conducted. Stakeholders were presented with a preselection of husbandry systems and were requested to modify or add systems according to their interest, and to name innovative practices to be tested. In total, 161 face-to-face interviews took place between October 2021 and March 2022, followed by 12 national and 3 European group meetings. Overall, stakeholders of all value chains were satisfied with the initially selected systems. Suggestions covered both mainstream systems as well as new, innovative ones, which are emerging due to the growing societal rejection of intensive farming practices. These included systems that improve the farms’ self-autonomy, use local resources or a circular economy, or improve animal welfare and environmental impact. Similarly, actors in all three value chains suggested innovative practices that centre on increased animal welfare and environmental sustainability, thus reflecting a willingness to respond to societal demands