Numerical simulation of the effects of various stud and hole configurations on friction hydro-pillar processing

• The UEL and FRIC subroutines and remeshing technology are useful for the analysis.
• The hole geometry influences the welding quality more strongly than that of stud.
• The stress and temperature distributions affect the welded quality.

This paper focuses on the effects of stud and hole configurations on weld defects in friction hydro-pillar processing (FHPP). Various configurations of the stud and hole are designed and all welds are performed by using a self-developed high-performance platform with the same welding parameters. The experimental results indicate that the defects usually appear at the bottom of the hole, but the upper region bonds well. The quality of welded joints is deeply affected by the bottom filling which is called initial stage. Therefore, the finite-element method (FEM) is employed to simulate the initial stage of FHPP. The simulated results agree well with those of the experiments. The results indicate that the geometry of the hole influences the welding quality more strongly than the shape of the stud and that weld samples with a rounded corner at the bottom of the hole bond well. Moreover, different shapes of the studs cause different stress states and temperature distributions, which also influence the quality of welded joints.