Dynamics modelling of spot welded joints

The determination of the dynamic characteristics of joints connecting structural components is a not yet solved problem of great importance when one intends to establish a theoretical model of the dynamic behaviour of a complex structure. Many of the problems found in such a process are in fact due to the difficulties related to the theoretical modelling of joints, be these connections of the classical type ? welded, bolted, riveted, etc. - or still more complicated, as elastic supports, ribbons, etc. Given the complexity of the problem, it is convenient to approach it considering each specific type of joint separately. In the present case, the work will focus on spot-welded joints of the type found in the body of automobile vehicles. Spot-welds connect laminated foils, limiting to small areas the effective connecting zones. As a consequence, the application of common finite element techniques to the analysis of the dynamic behaviour of the vehicle body, yields not very accurate results given the fact that the effects of the welded connections are not accounted for. The objective of this work is to develop a numeric model that characterizes those joints, so that a more accurate model of this type of structures may be available