> For the complete documentation index, see [llms.txt](https://dante-solutions-inc.gitbook.io/dante-6.3-help-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dante-solutions-inc.gitbook.io/dante-6.3-help-documentation/readme/material-models-for-aluminum-and-nickel-alloys/mechanical-plasticity-model-for-al-alloys.md).

# Mechanical Plasticity Model for AL Alloys

Internal state variable plasticity model is used to describe the yield behavior of aluminum alloys

$$Y = \frac{(0.5 \cdot (1.0 + \tanh(C\_{19} \cdot (C\_{20} - T))) \cdot (C\_3 + \text{pptfactor} \cdot (C\_{26} - C\_{27} \cdot T))}{(C\_{21} + \exp\left(\frac{-C\_4}{T}\right))}$$

Where *Cx* are plasticity model parameters, *T* is temperature, and *pptfactor* is the precipitate factor.

## Precipitate Factor (Aluminum and Nickel Alloys)

The precipitate factor affects the yield strength, isotropic and directional hardening of aluminum alloys. The alloy factor is calculated as the ratio of the current hardness to the matrix hardness, then subtract by 1.0. Its value range is \[1.0, ].