Modeling and simulation of the flow drill screw process of a DP590/Al6061-T6 multi-material joint used for vehicle body

Although the flow drill screw (FDS) joining technique has been successfully used for connecting dissimilar materials in lightweight structures design, forming simulation of the FDS joining process is still challenging, due to the fact that modeling of the severe plastic deformation and material failure is still difficult. In this work, the FDS forming process was successfully simulated through an optimized remeshing method for joining of the DP590/Al6061-T6 in lap structure as a case study. The effectiveness and accuracy of the numerical model developed in the current study were compared with those of the model based on the Lagrangian method and calibrated by experimental data. The results show that the FDS process can be simulated accurately through remeshing the distorted elements to regular tetrahedral elements, with accurate petal, bushing, and thread formed. And the local temperature rising surrounding the screw and axial force change of the FDS process were also predicted accurately. The simulation precision of the forming of the petal and bushing and the peak temperature are 95% and 2%, while the error of the first peak force is 19.3%. It was found that the forming of the petal and bushing is under the axial extrusion force, whereas the forming of the thread is under the plane extrusion force.