MAT4

MAT4 lets you define a hyper-elastic material model for NLFE elements based on the Mooney-Rivlin material model.

<MAT4

id = "integer"

mu01 = "real"

mu10 = "real"

nu = "real"

rho = "real"

YS = "real"

Unique material property identification number.

mu01

Material constant ().

mu10

Material constant ().

Poisson’s ratio for the element. Default is 0.49.

rho

Element density.

An elastic limit for strain. Default is 0.0.

YS >= 0.0

Comments

1.	This material element defines a hyper-elastic material that follows the Mooney-Rivlin material model law for the strain energy density function:

where

is the shear modulus

is the bulk modulus

is the Poisson’s ratio

Each element must have a unique material identification number.

2.	This material model can only be used with a fully parameterized element (BEAM12, QUAD12, TRIA12 and solid elements).

3.	mu10 and mu10 are material constants. mu10 can be determined using a tension or compression tests, however, mu01 should be determined using a biaxial test.

4.	YS lets you specify a maximum limit on the elastic strain that the component is allowed. If, during the simulation, the component strain (at any element in the component) exceeds this value, MotionSolve issues a warning message.

The example demonstrates the definition of a MAT4 element.