MATX82

Bulk Data Entry

MATX82 – Material Property Extension for Ogden Material for Geometric Nonlinear Analysis

Description

Defines additional material properties for Ogden material for geometric nonlinear analysis. This material is used to model rubber, polymers, and elastomers.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
MATX82	MID
	LAW	MU1	ALFA1	D1	MU2	ALFA2	D2
		MU3	ALFA3	D3	MU4	ALFA4	D4
		...

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
MAT1	102	10.0		0.495	6.0E-10
MATX82	102
	LAW	0.10	2.0		-0.010	-2.0

Field	Contents
MID	Material ID of the associated MAT1. See comment 1. No default (Integer > 0)
LAW	Indicates that material parameters MUi, ALFAi, and Di follow.
MUi	Parameter μi (Real)
ALFAi	Parameter αi (Real)
Di	Parameter Di (Real)

Comments

1.	The material identification number must be that of an existing MAT1 bulk data entry. Only one MATXi material extension can be associated with a particular MAT1.

2.	MATX82 is only applied in geometric nonlinear analysis subcases which are defined by ANALYSIS = EXPDYN. It is ignored for all other subcases.

3.	NU is defined on the corresponding MAT1. For material without Poisson effect, a small NU (for example, =1.E-10) should be defined.

4.	The strain energy density W is computed using the following equation:

matx82_1

with λi being the ith principal stretch, J = λ1 * λ2 * λ3 being the relative volume and .

5.	The Bulk Modulus K is:

If NU = 0,
matx82_3

If NU ≠ 0, then the value D1 is modified to respect
matx82_4

If NU = 0 and D1 = 0, then u = 0.475.

6.	The ground shear modulus is:

matx62_3

7.	This card is represented as a material in HyperMesh.