Page 73 - Using ANSYS for Finite Element Analysis A Tutorial for Engineers

60 • Using ansys for finite element analysis
(either isotropic or orthotropic), use one of the following: Command(s):
MPGUI:Main Menu > Preprocessor > Material Props > Material Models.
(See Material Model Interface for details on the GUI.) You also must spec-
ify the appropriate property label; for example, EX, EY, EZ for Young’s
modulus; KXX, KYY, KZZ for thermal conductivity; and so forth. For
isotropic material, you need to define only the X-direction property;
the other directions default to the X-direction value. For example: MP,
EX,1,2E11 ! Young’s modulus for material ref. no. 1 is 2E11
MP, DENS,1,7800 ! Density for material ref. no. 1 is 7800
MP, KXX,1,43 ! Thermal conductivity for material ref. no 1 is 43

2.2.1.8 nonlinear Material Properties

Nonlinear material properties are usually tabular data, such as plas-
ticity data (stress–strain curves for different hardening laws), magnetic
field data (B–H curves), creep data, swelling data, hyperelastic material
data, and so on. The first step in defining a nonlinear material property
is to activate a data table using the TB command (see Material Model
Interface for the GUI equivalent). For example, TB,BH,2 activates the
B–H table for material reference number 2. To enter the tabular data,
use the TBPT command. For example, the following commands define
a B–H curve:
TBPT,DEFI,150,.21
TBPT,DEFI,300,.55
TBPT,DEFI,460,.80
TBPT,DEFI,640,.95
TBPT,DEFI,720,1.0
TBPT,DEFI,890,1.1
TBPT,DEFI,1020,1.15
TBPT,DEFI,1280,1.25
TBPT,DEFI,1900,1.4