Solid to SPH Option (Sol2SPH)

The solid to SPH option (Sol2SPH) enables you to turn a solid element into particles in order to increase the time step/robustness of a Lagrangian calculation, while not significantly changing the physics.

It is compatible with the solid property options /PROP/TYPE14 (SOLID) and /PROP/TYPE6 (SOL_ORTH) and is limited to:

I_solid = 1, 2 or 24
I_frame = 1 or 2
8-node bricks (/BRICK including degenerated) and 4-node tetras (TETRA4), but not 10-node tetras.

The input is:

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PROP/SOLID/3
Prop example
#   Isolid    Ismstr               Icpre  Itetra10     Inpts   Itetra4    Iframe                  dn
         1         2                   0         0         0         0         1                   0
#                q_a                 q_b                   h            LAMBDA_V                MU_V
                   0                   0                   0                   0                   0
#             dt_min   istrain      IHKT
                   0         0         0
#     Ndir  SPH_part
         1        10
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

SPH_part: Part number defining the SPH properties
Ndir: Number of particles created for each direction, the maximum value is 9

Table 1. 8 Nodes Brick

`Ndir` = 1: 1 particle is created	`Ndir` = 2: 8 particles are created	`Ndir` = 3: 27 particles are created	`Ndir` = 4: 64 particles are created

The particles are created according to a cubic net.

Table 2. 4 Nodes Tetra

`Ndir` = 1: 1 particle is created	`Ndir` = 2: 4 particles are created	`Ndir` = 3: 10 particles are created	`Ndir` = 4: 22 particles are created

The transition from solid elements to SPH particles can be triggered by contact or by brick deletion.