mpoint attribute command

Syntax

mpoint attribute keyword ... <range>

Primary keywords:

biot-coefficient    biot-modulus    density    displacement    displacement-x    displacement-y    displacement-z    fluid-density    fluid-modulus    fluid-tension    permeability    pore-pressure    porosity    position    position-x    position-y    position-z    strain-xx    strain-xy    strain-xz    strain-yy    strain-yz    strain-zz    stress-xx    stress-xy    stress-xz    stress-yy    stress-yz    stress-zz    velocity    velocity-x    velocity-y    velocity-z

Set the value of mpoint attributes. This command is a synonym for the mpoint initialize command. Individual attributes can be listed with the mpoint list command and all attributes can be visualized.

biot-coefficient f

Mpoint Biot coefficient, used to compute changes in pore pressure (f = 1.0 by default). The Biot coefficient can only be set if the Biot mode is on, see the mpoint fluid biot command.

biot-modulus f

Mpoint Biot modulus, used to compute changes in pore pressure (f = 0.0 by default). The Biot modulus can only be set if the Biot mode is on, see the mpoint fluid biot command. If the Biot modulus is set, the fluid modulus is automatically adjusted using the porosity and assuming a Biot coefficient of 1. See Biot Coefficient and Biot Modulus.

density f

Mpoint density, where f > 0. By default, mpoint density is set to zero upon creation of an mpoint; a non-zero value is required for MPAC to properly compute mass properties and integrate the equation of motion on the background grid. An exception is thrown if an mpoint with zero density exists in the model when cycling starts.

displacement v

Accumulated mpoint displacement vector as a result of cycling.

displacement-x f

The \(x\)-component of the accumulated mpoint displacement as a result of cycling.

displacement-y f

The \(y\)-component of the accumulated mpoint displacement as a result of cycling.

displacement-z f (3D ONLY)

The \(z\)-component of the accumulated mpoint displacement as a result of cycling.

fluid-density f

Mpoint fluid density, where f > 0. By default, fluid density is set to 0.

fluid-modulus f

Mpoint fluid modulus, used to compute changes in pore pressure (f = 0.0 by default). The fluid modulus can only be set if the Biot mode is off, see mpoint fluid biot. If the fluid modulus is set, the Biot modulus is automatically adjusted using the porosity and the Biot coefficient is set to 1. See Biot Coefficient and Biot Modulus.

fluid-tension f

Mpoint fluid tension limit (f = -1e15 by default). This is the minimal (most tensile) pore pressure that can occur due to volumetric changes.

permeability f

The isotropic permeability coefficient of mpoint, \(k\) (e.g., m²/(Pa-sec) in SI units). In literature it is also referred to as the mobility coefficient. See Biot Coefficient and Biot Modulus for the relation between the permeability, the intrinsic permeability, \(\kappa\) (e.g., in m²), and the hydraulic conductivity, \(k_h\) (e.g., m/s). In MPAC only the permeability can be specified (and not the hydraulic conductivity as in FLAC).

pore-pressure f

Pore pressure of mpoint. The mpoint stress state remains unchanged.

porosity f

Mpoint porosity (f = 0.5 by default). If the Biot mode is off (see mpoint fluid biot), the Biot modulus is adjusted using the new porosity while keeping the fluid modulus constant. If the Biot mode is on, the fluid modulus is adjusted using the new porosity while keeping the Biot modulus constant.

position v

Location of mpoint.

position-x f

The \(x\)-component of the location of mpoint.

position-y f

The \(y\)-component of the location of mpoint.

position-z f (3D ONLY)

The \(z\)-component of the location of mpoint.

strain-xx f

The \(x\)-component of the mpoint strain.

strain-xy f

The \(xy\)-component of the mpoint strain.

strain-xz f (3D ONLY)

The \(xz\)-component of the mpoint strain.

strain-yy f

The \(yy\)-component of the mpoint strain.

strain-yz f (3D ONLY)

The \(yz\)-component of the mpoint strain.

strain-zz f (3D ONLY)

The \(zz\)-component of the mpoint strain.

stress-xx f

The \(x\)-component of the mpoint total stress.

stress-xy f

The \(xy\)-component of the mpoint total stress.

stress-xz f (3D ONLY)

The \(xz\)-component of the mpoint total stress.

stress-yy f

The \(yy\)-component of the mpoint total stress.

stress-yz f (3D ONLY)

The \(yz\)-component of the mpoint total stress.

stress-zz f (3D ONLY)

The \(zz\)-component of the mpoint total stress.

velocity v

Mpoint velocity vector.

velocity-x f

The \(x\)-component of the mpoint velocity.

velocity-y f

The \(y\)-component of the mpoint velocity.

velocity-z f (3D ONLY)

The \(z\)-component of the mpoint velocity.