Cyril LACROIX

• Mr Jean-François FONTAINE, Professor, Université de Bourgogne, Reviewer,
• Mr Serge SAMPER, Professor, Université de Rennes 1, Reviewer,
• Mr Alex BALLU, Associate Professor HDR, Université de Bordeaux 1, Examiner,
• Mr Hugo FALGARONE, Expert, Airbus Group Innovations, Examiner,
• Mr Luc MATHIEU, Professor, Université Paris Sud, Supervisor,
• Mr François THIEBAUT, Associate Professor, Université Paris Sud, Co-supervisor.

Abstract: The emergence of composite materials in aeronautics leads to lighter structures. However, these new materials induce new constraints to the assembly process. The adaptation is not yet complete. Indeed many operations are necessary to respect the new requirements, but are considered as non-productive. In the context of the European project LOCOMACHS, an assembly simulation tool is developed to limit the use of these operations. This thesis relates to the validation, from the measure, of the models used for flexible assembly simulation.

    A method to evaluate the geometry of a flexible component is implemented. The method compensates, by simulation, the effects of the environment on the component during its measurement. A sensitivity analysis of the method against changes in various measurement parameters and simulation parameters is performed in order to define a framework for implementation. Parameters of the model used to perform the compensation by simulation are not representative of the actual behavior. A modal analysis of deviations to a chosen reference geometry contributes to the adjustment of these parameters. This reference geometry is obtained by a reversal method applied in a flexible context to cancel some of the effects of the environment on the measured geometry of the component.

    The gap between the assembled components is the geometric key characteristic in an assembly of aeronautical composite structure. The assembly simulation, from measuring data of flexible components, enables to evaluate the gap between the components prior to assembly. Gap measurement methods in an assembly of flexible components are proposed, and they have been experimentally performed. The comparison of measured and simulated gaps highlights the performance of the simulation tool, and the difficulties in modeling actual measurement environment and actual assembly environment.

Keywords: Flexible Assembly, Geometrical Characterization, Measure, Geometrical deviations, Simulation of deflections, Gap, Experimental validation, LOCOMACHS.