Stress vs Strain graph for non-linear modelling

[Kanchan Stha]

Hello everyone,
I am a beginner here. I am modelling the masonry wall in Strand 7. I am having difficulties inputting the stress vs strain graph in the material properties of each component of masonry. Can anyone please guide me on this? Thank you

 

[FEA way]

To define nonlinear material behavior in any FEA software you will need a good source of data. Either results of physical tests (like basic uniaxial tension one) or literature. For metals, there is for example a book titled "Atlas of Stress-Strain Curves". In the case of other types of materials, it might be more difficult to find full stress-strain curves but if you search for particular material on the internet, you may find research papers that feature such data from experiments carried out by authors. The simplest approach (elastic-perfectly plastic material) requires only yield stress to define plastic behavior, for more advanced plasticity models you will need stress-strain data points or tangent moduli, depending on the software.