4.14.5.7. Modified Ibarra-Medina-Krawinkler Deterioration Model with Pinched Hysteretic Response (ModIMKPinching Material)ΒΆ

uniaxialMaterial('ModIMKPinching', matTag, K0, as_Plus, as_Neg, My_Plus, My_Neg, FprPos, FprNeg, A_pinch, Lamda_S, Lamda_C, Lamda_A, Lamda_K, c_S, c_C, c_A, c_K, theta_p_Plus, theta_p_Neg, theta_pc_Plus, theta_pc_Neg, Res_Pos, Res_Neg, theta_u_Plus, theta_u_Neg, D_Plus, D_Neg)

This command is used to construct a ModIMKPinching material. This material simulates the modified Ibarra-Medina-Krawinkler deterioration model with pinching hysteretic response. NOTE: before you use this material make sure that you have downloaded the latest OpenSees version. A youtube video presents a summary of this model including the way to be used within openSees youtube link.

matTag (int)

integer tag identifying material

K0 (float)

elastic stiffness

as_Plus (float)

strain hardening ratio for positive loading direction

as_Neg (float)

strain hardening ratio for negative loading direction

My_Plus (float)

effective yield strength for positive loading direction

My_Neg (float)

effective yield strength for negative loading direction (Must be defined as a negative value)

FprPos (float)

Ratio of the force at which reloading begins to force corresponding to the maximum historic deformation demand (positive loading direction)

FprNeg (float)

Ratio of the force at which reloading begins to force corresponding to the absolute maximum historic deformation demand (negative loading direction)

A_pinch (float)

Ratio of reloading stiffness

Lamda_S (float)

Cyclic deterioration parameter for strength deterioration [E_t=Lamda_S*M_y, see Lignos and Krawinkler (2011); set Lamda_S = 0 to disable this mode of deterioration]

Lamda_C (float)

Cyclic deterioration parameter for post-capping strength deterioration [E_t=Lamda_C*M_y, see Lignos and Krawinkler (2011); set Lamda_C = 0 to disable this mode of deterioration]

Lamda_A (float)

Cyclic deterioration parameter for accelerated reloading stiffness deterioration [E_t=Lamda_A*M_y, see Lignos and Krawinkler (2011); set Lamda_A = 0 to disable this mode of deterioration]

Lamda_K (float)

Cyclic deterioration parameter for unloading stiffness deterioration [E_t=Lamda_K*M_y, see Lignos and Krawinkler (2011); set Lamda_K = 0 to disable this mode of deterioration]

c_S (float)

rate of strength deterioration. The default value is 1.0.

c_C (float)

rate of post-capping strength deterioration. The default value is 1.0.

c_A (float)

rate of accelerated reloading deterioration. The default value is 1.0.

c_K (float)

rate of unloading stiffness deterioration. The default value is 1.0.

theta_p_Plus (float)

pre-capping rotation for positive loading direction (often noted as plastic rotation capacity)

theta_p_Neg (float)

pre-capping rotation for negative loading direction (often noted as plastic rotation capacity) (must be defined as a positive value)

theta_pc_Plus (float)

post-capping rotation for positive loading direction

theta_pc_Neg (float)

post-capping rotation for negative loading direction (must be defined as a positive value)

Res_Pos (float)

residual strength ratio for positive loading direction

Res_Neg (float)

residual strength ratio for negative loading direction (must be defined as a positive value)

theta_u_Plus (float)

ultimate rotation capacity for positive loading direction

theta_u_Neg (float)

ultimate rotation capacity for negative loading direction (must be defined as a positive value)

D_Plus (float)

rate of cyclic deterioration in the positive loading direction (this parameter is used to create assymetric hysteretic behavior for the case of a composite beam). For symmetric hysteretic response use 1.0.

D_Neg (float)

rate of cyclic deterioration in the negative loading direction (this parameter is used to create assymetric hysteretic behavior for the case of a composite beam). For symmetric hysteretic response use 1.0.

See also

Notes