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Why a Particle-Based Method? (2)
• ALEformulation: the mesh moves arbitrarily
∪ Simple and elegant treatment of Fluid-Structure Interaction (permanent!)
∪ Combines advantages of Lag./Eul. without respective drawbacks
∩ Mesh rezoning has limitations (e.g. with fragmentation) and is difficult to
do e.g. in the presence of rotating bodies
• SPHformulation: the mesh is made of particles (no
standard connectivity)
∪ Same advantages as the Lagrangian formulation: easy B.C.s and
only the real domain is modelled
∪ Without the associated drawbacks: the mesh does not “deform”
∩ Recalculation of connectivity at each step is costly
∩ More difficult representation of material laws
∩ Relatively “young” method
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SPH Formulation
• Developed in the ’70s for astrophysical problems (Lucy,
Gingold, Monaghan, 1977) involving the motion of
compressible fluids in complex geometries
• It may be effectively coupled with standard FE to model
impact phenomena with fragmentation
• The approach is Lagrangian and has the advantage of not
using a mesh in the traditional sense, so that all problems
related to excessive mesh distortions are avoided
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