Generic Hysteretic Model - hyst_mat

The hyst_mat is a generic uniaxial material model characterised by Pinching effect (controlled by a pinching factor with values from 0 for no pinching to 1 for high pinching) and by four deterioration modes including strength deterioration, peak stress deterioration, reloading and unloading stiffness deterioration. All deterioration modes are controlled by the deterioration factor (with values from 0 for no deterioration to 1 for high deterioration). An initial backbone curve consisting of the yielding point, the peak stress point and the residual strength is initially defined and deteriorates after each unloading incident. Thirteen parameters are needed in order to describe the mechanical characteristics of the material. Pairs of stress strain defining the backbone curve must be given in ascending order:

Elastic Stiffness (Ke)
The default value is 200000.

Yield Stress in positive direction (σy,pos)
The default value is 300MPa.

Yield Stress in negative direction (σy,neg)
The default value is 300MPa.

Peak Strain in positive direction (εpeak,pos)
The default value is 0.3mm/mm.

Peak stress in positive direction (σpeak,pos)
The default value is 500MPa..

Peak Strain in negative direction (εpeak,neg)
The default value is 0.3mm/mm.

Peak stress in negative direction (σpeak,neg)
The default value is 500 MPa.

Residual strength in positive direction (σres,pos)
The default value is 120MPa.

Residual strength in negative direction (σres,neg)
The default value is 120MPa.

Pinching factor (Fpinch)
The factor controlling the pinching of the model with zero value for no pinching and value equal to 1 for highest pinching. The default value is 0.5.

Deteroration Factor (Fdet)
The factor controlling the deterioration of the model with zero value for no deterioration and value equal to 1 for highest deterioration. The default value is 0.5.

Specific weight ()
This is the specific weight of the material. The default value is 18 kN/m3.