Bulk Data Entry Defines the material properties for linear, temperature-independent, and isotropic materials.


(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
  ST SC SS            
  MODULI MTIME              
  RAYL ALPHA BETA            


(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MAT1 17 3.+7   0.33 4.28        


Field Contents SI Unit Example
MID Unique material identification.
Specifies an identification number for this material.
Specifies a user-defined string label for this material entry. 2

No default (Integer > 0 or <String>)

E Young's modulus.

Default = blank (Real or blank)

G Shear modulus.

Default = blank (Real or blank)

NU Poisson's ratio.

If < 0.0, a warning is issued.

Default = blank (-1.0 < Real < 0.5 or blank)

RHO Mass density. Used to automatically compute mass for all structural elements.

No default (Real)

A Thermal expansion coefficient.

No default (Real)

TREF Reference temperature for thermal loading.

Default = 0.0 (Real)

GE Structural element damping coefficient. 10 11

No default (Real)

ST, SC, SS Stress limits in tension, compression and shear. Used for composite ply failure calculations.

No default (Real)

MODULI Continuation line flag for moduli temporal property. 12  
MTIME Material temporal property. This field controls the interpretation of the input material property for viscoelasticity.
This material property is considered as the Instantaneous material input for viscoelasticity on the MATVE entry.
LONG (Default)
This material property is considered as the Long-term relaxed material input for viscoelasticity on the MATVE entry.
RAYL Continuation line flag for material-dependent Rayleigh damping.  
ALPHA Material-dependent Rayleigh Damping coefficient for the mass matrix.

Default = blank (Real ≥ 0.0)

BETA Material-dependent Rayleigh Damping coefficient for the stiffness matrix.

Default = blank (Real ≥ 0.0)



  1. The material identification number/string must be unique for all MAT1, MAT2, MAT8 and MAT9 entries.
  2. String based labels allow for easier visual identification of materials, including when being referenced by other cards. (example, the MID field of properties). For more details, refer to String Label Based Input File in the Bulk Data Input File.
  3. Either E or G must be specified (that is, non-blank).
  4. If any one of E, G, or NU is blank, it is computed to satisfy the identity,

    E = 2(1+NU)G; otherwise, values supplied by you are used.

  5. If E and NU are both blank, they are both given the value 0.0.
  6. If G and NU are both blank, they are both given the value 0.0.
  7. Unlikely data on one or more MAT1 entries result in a warning message. Unlikely data is defined as:
    • E < 0.0 or
    • G < 0.0 or
    • NU > 0.5 or
    • NU < -1.0 or
    • | 1 E 2 ( 1 + NU ) G | > 0.01
    • except for cases covered by comments 5 and 6.
  8. It is strongly recommended that only two of the three values E, G, and NU be input.
  9. The large field format may also be used.
  10. To obtain the damping coefficient GE, multiply the critical damping ratio, C / C 0 MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qaiaac+ cacaWGdbWaaSbaaSqaaiaaicdaaeqaaaaa@391F@ by 2.0.
  11. TREF and GE are ignored, if a MAT1 entry is referenced by a PCOMP, PCOMPP, or PCOMPG Bulk Data Entries.
  12. MODULI continuation line is only applicable when used together with the MATVE entry. Refer to MATVE which provides additional information on how this material input is interpreted.
  13. This card is represented as a material in HyperMesh.
    Element Type E NU G
    CROD, CBAR, CBEAM, and CWELD Axial and Bending N/A Transverse Shear and Torsion
    CSHEAR N/A N/A Shear
    CQUAD and CTRIA Membrane and Bending Membrane and Bending Transverse Shear