Developpement d'une methode de calcul des contraintes residuelles pour la methode des contours et mesures experimentales des contraintes residuelles de joints soudes en T sous l'influence de bridage

This research involves two specific objectives. Initially, it is proposed to demonstrate the applicability of the constant pressure cell method (CPM), based on the influence functions established by Love from the Boussinesq and Cerruti equations for calculating residual stresses using the contour method. The motivations to use CPM instead of FEM are time savings and accuracy of solutions. To this end, an algorithm is developed and solutions are validated by means of finites elements method (FEM). For comparable precision level, the CPM requires up to four times less elements than the MEF, and thereby, may proportionally reduce computing time.;In addition, a new approach is proposed to calculate accurately the restraint intensity for T joints. This approach is determined from the dominant movements in the thermal shrinkage of the filler metal. The different approaches of evaluating intensity are used to determine the interaction between the clamping intensity and the residual stress measured with strain gauges and calculated by the contours method in the T-joints.;Keywords: Restraint intensity, Welding, Constant pressure cell method (CPM), Contour method.;The second objective of the research program is to link the restraint intensity level of welded T joints with induced residual stresses. A series of test is conducted. Each test is performed using a restraint device to obtain maximum rigidity. The restraint intensity is controlled by the plates thickness. In addition, the plates are instrumented with gauges and thermocouples throughout the welding process to collect deformation and temperature values inherent to the process. The internal stresses are also studied through the contour method. The algorithm developed above is used. The displacement field is generated by an EDM cut at the center of each tested assembly.