L'operation de soudage introduit des champs de contraintes residuelles qu'il est aujourd'hui possible d'evaluer, soit experimentalement, soit par le calcul. La connaissance de ces contraintes dans les structures soudees est utile pour comprendre les phenomenes d'endommagement et de ruine de ces structures. Cet article presente les avancees recentes obtenues dans le cadre du developpement d'une methode ultrasonore de mesure de contraintes. Cette methode a comme avantage potentiel d'etre non destructive, applicable sur site et facile a mettre en oeuvre.
Recent developments in measurements of the residual stresses by ultrasonic method. The main sources of errors. . Welding causes deformation of welded joints leading to the occurrence of residual stresses. Now, it is possible to evaluate the field of residual stresses, whether experimentally, or by calculation. The knowledge of the distribution and level of the residual stresses in welded components is an important factor, particularly for predicting the damaging and ruin phenomena of these components. This paper presents recent advances obtained in the field of an ultrasonic method for stress measurements. This method is potentially advantageous because it is nondestructive, easy and fast to use in situ. In the paper are presented the results obtained with ultrasonics on steel welded plate, and comparison is made with stress measurements obtained by incremental step-by-step hole drilling method. These results are also discussed after offset and ''microstructure'' corrections. The paper discusses also the influence of the principal sources of errors and the precision obtained.