A particle method for elastic and visco-plastic structures and fluid-structure interactions

A new particle method is proposed for elastic and visco-plastic structures based on the concept of MPS (Moving Particle Semi-implicit) method which was developed for fluid dynamics. Particle interaction models for differential operators are prepared in MPS method. The government equations of elastic structures are interpreted into interactions among particles. These interactions are equivalent to those of normal and tangential springs. Therefore the present particle method is simple and corresponding physical meaning is clear. Model for viscoplastic structure is represented to replace these elastic springs into visco-plastic ones. Elements or grids are not necessary. A tensile plate and a cantilever beam as elastic structures are analyzed by the present method. The results are in good agreement with theoretical solutions. Viscoplastic analysis for creep deformation and fracture of a cracked plate is also carried out and the result is in good agreement with an experiment. The present particle method for elastic structures is combined with MPS method for fluid-structural interaction problems. Since both methods are based on the same particle modeling in Lagrangian coordinates, large deformation of the interfaces can be easily analyzed. Water falling on a cantilever beam is analyzed by the combined method. Crash of water and resultant displacement of the beam are successfully analyzed. Structural analysis in a breakwater is carried out with wave propagation. The calculated pressure distribution on the breakwater is in good agreement with a theory.