Simulation of two-way interaction between sealant and structural parts as applied to large-scale aircraft assembly

Wet assembly is the most common method of joining parts in the aircraft industry. In this case, a layer of liquid sealant is applied to the contact surface of one of the parts, after which the structure is bolted. Despite the practical importance of this issue, until now there has been no mathematical model or software tool that would allow simulating the wet assembly process. This study is devoted to modeling the wet assembly process of large-scale aircraft structures, taking into account the flow of sealant applied between the joined parts. The original mathematical model includes a full two-way interaction of deformable parts and a viscous liquid sealant. Such effects as contact interaction of parts, the presence of the free surface of sealant layer, the sealant curing, deformation and loosening of fasteners are taken into account. The developed mathematical model is applied to the simulation of the assembly process of wing to fuselage upper joint. A special full-scale model has been developed in order to reproduce the effects observed in practical assembly. The numerous numerical experiments demonstrate these effects and illustrate how different parameters of the process affect both intermediate and final results of the assembly. The performed investigation shows how mathematical modeling can contribute to the improvement of existing and development of new technologies on the assembly lines of aircraft manufacturing companies, where any experiments are extremely expensive or simply impossible.