uniaxialMaterial('Pinching4', matTag,ePf1, ePd1, ePf2, ePd2, ePf3, ePd3, ePf4, ePd4, <eNf1, eNd1, eNf2, eNd2, eNf3, eNd3, eNf4, eNd4>, rDispP, rForceP, uForceP, <rDispN, rForceN, uForceN>, gK1, gK2, gK3, gK4, gKLim, gD1, gD2, gD3, gD4, gDLim, gF1, gF2, gF3, gF4, gFLim, gE, dmgType)
This command is used to construct a uniaxial material that represents a 'pinched' load-deformation response and exhibits degradation under cyclic loading. Cyclic degradation of strength and stiffness occurs in three ways: unloading stiffness degradation, reloading stiffness degradation, strength degradation.
matTag |
integer tag identifying material |
ePf1 ePf2 ePf3 ePf4 |
floating point values defining force points on the positive response envelope |
ePd1 ePd2 ePd3 ePd4 |
floating point values defining deformation points on the positive response envelope |
eNf1 eNf2 eNf3 eNf4 |
floating point values defining force points on the negative response envelope |
eNd1 eNd2 eNd3 eNd4 |
floating point values defining deformation points on the negative response envelope |
rDispP |
floating point value defining the ratio of the deformation at which reloading occurs to the maximum historic deformation demand |
fFoceP |
floating point value defining the ratio of the force at which reloading begins to force corresponding to the maximum historic deformation demand |
uForceP |
floating point value defining the ratio of strength developed upon unloading from negative load to the maximum strength developed under monotonic loading |
rDispN |
floating point value defining the ratio of the deformation at which reloading occurs to the minimum historic deformation demand |
fFoceN |
floating point value defining the ratio of the force at which reloading begins to force corresponding to the minimum historic deformation demand |
uForceN |
floating point value defining the ratio of strength developed upon unloading from negative load to the minimum strength developed under monotonic loading |
gK1 gK2 gK3 gK4 gKLim |
floating point values controlling cyclic degradation model for unloading stiffness degradation |
gD1 gD2 gD3 gD4 gDLim |
floating point values controlling cyclic degradation model for reloading stiffness degradation |
gF1 gF2 gF3 gF4 gFLim |
floating point values controlling cyclic degradation model for strength degradation |
gE |
floating point value used to define maximum energy dissipation under cyclic loading. Total energy dissipation capacity is defined as this factor multiplied by the energy dissipated under monotonic loading. |
dmgType |
string to indicate type of damage (option: 'cycle' , 'energy' ) |