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Friction-Stir Welding Using LS-DYNA Smooth Particle Hydrodynamics (SPH)

Friction Stir Welding (FSW) 

  • Friction stir welding (FSW) is a solid-state joining process that creates high-quality welds in metals, primarily aluminum and its alloys. It involves a rotating tool that plunges into the joint between two workpieces.
  • The tool generates heat and softens the material without melting it. As the tool rotates, it stirs and mixes the softened material, forming a solid-state bond.
  • FSW has advantages such as minimal distortion, and the ability to join dissimilar materials.
  • It is used in the aerospace and automotive industries to manufacture strong and reliable components.

Figure 1: Friction Welding Process

LS-DYNA Smooth Particle Hydrodynamics (SPH)

  • The SPH method is a Lagrangian mesh-free numerical technique that can be used to simulate different physics from fluid dynamics problems as well as for structural problems that contain high speed and large deformation.
  • This method discretizes the continuum domain into particles, where each particle carries certain properties like mass, velocity, and other relevant variables.
  • Like FEM Method, the SPH method solves conservation equations to solve for velocity, pressure and energy.
  • These particles interact with each other based on the smoothing function (SPH kernel function), which determines the rate of change of influence neighbouring particles each other.

Conservation Equations

Support Domain 2D Representation

Kernel function 2D Representation


  • Below are animations illustrating friction stir welding simulation utilizing Smooth Particle Hydrodynamics:


Animation 1: Friction Stir Welding Result


Animation 2: Friction Stir Welding Temperature Result By Time


Post by Kamil Koyunlu
August 11, 2023