Plasticity materials implement their yield behavior by combining them with hardening laws. The material definition sets the equation of state properties for the material and the selected hardening law determines the yield criterion.
Selecting a Hardening Law
Hardening laws are assigned to materials within their material definition. In scripted files, a hardening law is added within a material command block as follows:
Material ID,name,type . Hardening (Law_Name or number) Law_Property (value) . . Done
Selecting a hardening law in an XML input file has the form:
<Material Type='#' Name='name'> . <Hardening>(Law_Name or number)</Hardening> <Law_property>(value)</Law_property> . </Material>
In both these options:
- (Law_Name or number) is the name or number of the desired hardening law (see table of available hardening laws).
- Law_Property - after selecting the hardening law, set all required properties for that law. Refer to each hardening law for the names and descriptions of properties that can be set. Replace the command name Law_Property with the property name and set (value) is the value for that property.
Available Hardening Laws
Materials that allow hardening laws can pick them from the following table. Unless otherwise stated, any such material can use any hardening law. By mixing and matching materials and hardening laws you have options for many types of materials. A single material definition, however, can only use one hardening law.
|Linear||1||Linear hardening (which includes elastic-plastic as a special case)|
|Nonlinear||2||Nonlinear hardening law|
|Nonlinear2||6||An alternate nonlinear hardening law|
|JohnsonCook||3||Johnson Cook hardening law|
|SCGL||4||Steinberg-Cochran-Guinan hardening law|
|SL||5||Steinberg-Lund hardening law|
|DDB-PPM||7||A dislocation density based polycrystal plasticity model|