Accurate simulation of Sealing process using a GPU-accelerated Lagrangian differencing dynamics method

A vehicle body is a complex geometric object consisting of many parts. This inevitably creates a lot of seams and gaps through which water, dust, and sound waves can penetrate inside. To prevent corrosion of the body and reduce noise in the car, such gaps are sealed with a special paste with complex non-Newtonian rheological properties. Sealing also has a cosmetic function for visible regions on the finished vehicle, which increases the requirement for quality of the seams. Sealing seams are applied using special robotic arms. Seam length can reach several meters with a height of 0.5-5mm and a width of 5-40mm. In this situation, optimizing the robotic arms paths and the flowrate of expensive sealant can significantly speed up the production process and reduce its cost. Accurate and fast CFD modelling makes it possible to plan the sealing process in advance, which shortens the development cycle of new vehicles and reduces the likelihood of unexpected costs. This paper presents a new framework for modelling the sealing processes using CFD solver that is based on a novel meshfree Lagrangian Differencing Dynamics (LDD) approach, which considers the viscoelastic properties of the sealant material and the moving robotic arm nozzles. LDD allows to simplify pre-processing and does not require the user to perform time-consuming and complex meshing. The use of the LDD approach in combination with GPU technologies will make it possible to conduct high-precision simulation of the sealing process of real objects in a few hours on a standard computer. In this paper, we present the basic introduction of the sealing, the fundamental formulations of the LDD method and the involved mathematical model, the implementation details, the validation, and eventually the simulation results on a realistic car geometry with practical complex robotic movements.