A finite element approach to the integrated modelling of the incremental forming of friction stir welded sheets

Thin sheet components are increasingly used in several advanced industries, such as aerospace and automotive. In these sectors, improved mechanical and surface properties are highly demanded meeting, in several cases, also weight and aesthetical requirements. The industrial routes typically involved in the manufacturing of this kind of components are based on the combination of joining, forming and cutting technologies, whereas efficient production strategies are planned adopting modelling and simulations based on an integrated approach. The present work deals with the development of an integrated numerical model able to simulate the manufacturing route for formed thin sheets, rolled, welded by friction stir welding (FSW) technology and finally shaped by means of a single point incremental forming (SPIF) process. In concept, the approach is based on the link between two submodels simulating the two consecutive processes. The first submodel, taking as input the geometry and the mechanical properties of the anisotropic rolled aluminum foil, simulates in the ABAQUS environment, the FSW process. Tool geometry and path, rotational velocity, advancing speed, and other material parameters are defined as input values, providing, as output, the mechanical properties of the welded sheet, the affected zones, and the residual stress-strain fields. This output feeds the SPIF sub-model that evaluates the deformation of the sheet according to a defined process planning, allowing for the simulation of the entire manufacturing chain