mp

Mapdl.mp(lab='', mat='', c0='', c1='', c2='', c3='', c4='', **kwargs)

APDL Command: MP

Defines a linear material property as a constant or a function of temperature.

Parameters
  • lab

    Valid material property label. Applicable labels are listed under “Material Properties” in the input table for each element type in the Element Reference. See Linear Material Properties in the Material Reference for more complete property label definitions:

    ALPD - Mass matrix multiplier for damping.

    ALPX - Secant coefficients of thermal expansion (also ALPY, ALPZ).

    BETD - Stiffness matrix multiplier for damping.

    Note: If used in an explicit dynamic analysis, the value corresponds to the percentage of damping in the high frequency domain. For example, 0.1 roughly corresponds to 10% damping in the high frequency domain.

    BETX - Coefficient of diffusion expansion (also BETY, BETZ)

    BVIS - Bulk viscosity

    C - Specific heat

    CREF - Reference concentration (may not be temperature dependent)

    CSAT - Saturated concentration

    CTEX - Instantaneous coefficients of thermal expansion (also CTEY, CTEZ)

    CVH - Heat coefficient at constant volume per unit of mass

    DENS - Mass density.

    DMPR - Constant structural damping coefficient in full harmonic analysis or damping ratio in mode-superposition

    analysis.

    DXX - Diffusivity coefficients (also DYY, DZZ)

    EMIS - Emissivity.

    ENTH - Enthalpy.

    EX - Elastic moduli (also EY, EZ)

    GXY - Shear moduli (also GYZ, GXZ)

    HF - Convection or film coefficient

    KXX - Thermal conductivities (also KYY, KZZ)

    LSST - Electric loss tangent

    LSSM - Magnetic loss tangent

    MGXX - Magnetic coercive forces (also MGYY, MGZZ)

    MURX - Magnetic relative permeabilities (also MURY, MURZ)

    MU - Coefficient of friction

    NUXY - Minor Poisson’s ratios (also NUYZ, NUXZ) (NUXY = νyx, as described in Stress-Strain Relationships in the

    Mechanical APDL Theory Reference)

    PERX - Electric relative permittivities (also PERY, PERZ)

    Note: If you enter permittivity values less than 1 for SOLID5, PLANE13, or SOLID98, the program interprets the values as absolute permittivity. Values input for PLANE223, SOLID226, or SOLID227 are always interpreted as relative permittivity.

    PRXY - Major Poisson’s ratios (also PRYZ, PRXZ) (PRXY = νxy, as described in Stress-

    Strain Relationships in the Mechanical APDL Theory Reference)

    QRATE - Heat generation rate for thermal mass element MASS71. Fraction of plastic work

    converted to heat (Taylor-Quinney coefficient) for coupled- field elements PLANE223, SOLID226, and SOLID227.

    REFT - Reference temperature. Must be defined as a constant; C1 through C4 are

    ignored.

    RH - Hall Coefficient.

    RSVX - Electrical resistivities (also RSVY, RSVZ).

    SBKX - Seebeck coefficients (also SBKY, SBKZ).

    SONC - Sonic velocity.

    THSX - Thermal strain (also THSY, THSZ).

    VISC - Viscosity.

  • mat – Material reference number to be associated with the elements (defaults to the current MAT setting [MAT]).

  • c0 – Material property value, or if a property-versus-temperature polynomial is being defined, the constant term in the polynomial. C0 can also be a table name (%tabname%); if C0 is a table name, C1 through C4 are ignored.

  • c1 – Coefficients of the linear, quadratic, cubic, and quartic terms, respectively, in the property-versus-temperature polynomial. Leave blank (or set to zero) for a constant material property.

  • c2 – Coefficients of the linear, quadratic, cubic, and quartic terms, respectively, in the property-versus-temperature polynomial. Leave blank (or set to zero) for a constant material property.

  • c3 – Coefficients of the linear, quadratic, cubic, and quartic terms, respectively, in the property-versus-temperature polynomial. Leave blank (or set to zero) for a constant material property.

  • c4 – Coefficients of the linear, quadratic, cubic, and quartic terms, respectively, in the property-versus-temperature polynomial. Leave blank (or set to zero) for a constant material property.

Notes

MP defines a linear material property as a constant or in terms of a fourth order polynomial as a function of temperature. (See the TB command for nonlinear material property input.) Linear material properties typically require a single substep for solution, whereas nonlinear material properties require multiple substeps; see Linear Material Properties in the Material Reference for details.

If the constants C1 - C4 are input, the polynomial

Property = C0 + C1(T) + C2(T)2 + C3(T)3 + C4(T)4

is evaluated at discrete temperature points with linear interpolation between points (that is, a piecewise linear representation) and a constant-valued extrapolation beyond the extreme points. First-order properties use two discrete points (±9999°). The MPTEMP or MPTGEN commands must be used for second and higher order properties to define appropriate temperature steps. To ensure that the number of temperatures defined via the MPTEMP and MPTGEN commands is minimally sufficient for a reasonable representation of the curve, ANSYS generates an error message if the number is less than N, and a warning message if the number is less than 2N. The value N represents the highest coefficient used; for example, if C3 is nonzero and C4 is zero, a cubic curve is being used which is defined using 4 coefficients so that N = 4.