3.1.5.15. Hysteretic Material

This command is used to construct a uniaxial hysteretic material object with pinching of force and deformation, damage due to ductility and energy, and degraded unloading stiffness based on ductility. The backbone can be either bilinear or trilinear.

uniaxialMaterial Hysteretic $matTag $s1p $e1p $s2p $e2p <$s3p $e3p> $s1n $e1n $s2n $e2n <$s3n $e3n> $pinchX $pinchY $damage1 $damage2 <$beta>

Argument	Type	Description
$matTag	integer	Integer tag identifying material
$s1p $e1p	float	stress and strain (or force & deformation) at first point of the envelope in the positive direction
$s2p $e2p	float	stress and strain (or force & deformation) at second point of the envelope in the positive direction
$s3p $e3p	float	stress and strain (or force & deformation) at third point of the envelope in the positive direction (optional)
$s1n $e1n	float	stress and strain (or force & deformation) at first point of the envelope in the negative direction
$s2n $e2n	float	stress and strain (or force & deformation) at second point of the envelope in the negative direction
$s3n $e3n	float	stress and strain (or force & deformation) at third point of the envelope in the negative direction (optional)
$pinchx	float	pinching factor for strain (or deformation) during reloading
$pinchy	float	pinching factor for stress (or force) during reloading
$damage1	float	damage due to ductility: D1(mu-1)
$damage2	float	damage due to energy: D2(Eii/Eult)
$beta	float	power used to determine the degraded unloading stiffness based on ductility, mu-beta (optional, default=0.0)

Code Developed by: |Michael Scott (Oregon State University) & Filip Filippou (UC Berkeley)|