Keyword type: model definition, material
This option is used to define the thermal expansion coefficients of a material. They are interpreted as total expansion coefficients with respect to a reference temperature ![]() , i.e. the thermal strain
, i.e. the thermal strain 
![]() of a material at a final temperature T and with initial temperature
 of a material at a final temperature T and with initial temperature ![]() is determined by
 is determined by 
| (398) | 
where ![]() is the thermal coefficient at a temperature T. There are two optional parameters TYPE and ZERO. Default for TYPE is TYPE=ISO, other values are TYPE=ORTHO for orthotropic materials and TYPE=ANISO for anisotropic materials. All constants may be temperature dependent. The parameter ZERO is used to determine the reference temperature, default is 0.
 is the thermal coefficient at a temperature T. There are two optional parameters TYPE and ZERO. Default for TYPE is TYPE=ISO, other values are TYPE=ORTHO for orthotropic materials and TYPE=ANISO for anisotropic materials. All constants may be temperature dependent. The parameter ZERO is used to determine the reference temperature, default is 0.
First line:
Following line for TYPE=ISO:
Following line for TYPE=ORTHO:
Following line for TYPE=ANISO:
Example: *EXPANSION,ZERO=273. 12.E-6,373. 20.E-6,573.
tells you that the thermal strain in a body made of this material is
![]() if heated from T=273 to T=373, and
 if heated from T=273 to T=373, and 
![]() if heated from T=273 to T=573.
 if heated from T=273 to T=573.
Example files: beamt, beamt2.