D3PLOT 22.1

The Results Available for SPH Elements

The results available for SPH elements

SPH elements write out the following block of 18 values per element to the .PTF file:

  • Radius of influence (1 value, used to determine its size when drawn)
  • Pressure (1 value)
  • Stress tensor (6 values)
  • Plastic strain (1 value)
  • Density (1 value)
  • Internal energy (1 value)
  • Number of neighbours (1 value)
  • Strain tensor (6 values)

Experience suggests that the above data components are written regardless of any flags on *DATABASE_EXTENT_BINARY or other control cards.

The following tables show the raw data component names, and also those derived by D3PLOT.

Symmetric stress tensor

X_DIRECT_STRESS

Y_DIRECT_STRESS

Z_DIRECT_STRESS

XY_SHEAR_STRESS

YZ_SHEAR_STRESS

ZX_SHEAR_STRESS

This is written in the global cartesian coordinate system.

The stress components that can be derived this by D3PLOT are:

MAX_PRINC_STRESS

MID_PRINC_STRESS

MIN_PRINC_STRESS

YIELD_UTILISATION_FACTOR

MAX_DEV_PRINC_STRESS

MID_DEV_PRINC_STRESS

MIN_DEV_PRINC_STRESS

YIELD_UTILISATION_PERCENTAGE

VON_MISES_STRESS

SIGNED_VON_MISES_STRESS

MAX_SHEAR_STRESS

LODE_PARAMETER

PRESSURE

TRIAXIALITY

LODE_ANGLE

LODE_PARAMETER_ALT

Effective plastic strain

PLASTIC_STRAIN

The effective plastic strain is always output, as above. It has no intrinsic direction.

Directional strain tensor

Unlike other element types this strain tensor is written unconditionally, regardless of the value of STRFLG on the *DATABASE_EXTENT_BINARY card.

SX_DIRECT_STRAIN

SY_DIRECT_STRAIN

SZ_DIRECT_STRAIN

SXY_SHEAR_STRAIN

SYZ_SHEAR_STRAIN

SZX_SHEAR_STRAIN

And the strains derived from these by D3PLOT

SMAX_PRINC_STRAIN

SMID_PRINC_STRAIN

SMIN_PRINC_STRAIN

SVON_MISES_STRAIN

SMAX_SHEAR_STRAIN

PEMAG_PLAST_STRN_MAG

SAV_AVERAGE_STRAIN

Further SPH-only components

RADIUS

VOLUME

DENSITY

NUM_NEIGHBOURS

ENERGY

PRESSURE

It is not clear why PRESSURE is written separately, rather than being deduced from the stress tensor. D3PLOT uses this value rather than (Sx + Sy + Sz) / -3.0


The following are derived from the above:

VOLUME (from radius)