Bilinear Hysteretic Spring > Stiffness Parameters
Bilinear Hysteretic isolator is used for dynamic time history analysis when Non-linear dampers option is selected under Recalc pad. Damper has linear stiffness in static calculation and dynamic properties for time history calculation. Bilinear Hysteretic element is active for all translations degrees of freedom. Element does not consider any p-delta effects occurring due to axial load and translation of bearing.
| Setting | Description |
|---|---|
| From/To/Step | Element series, for which the section properties are input/modified. |
| Element type | Bilinear Hysteretic Spring (BiHyst): Type name of the isolator. |
| Element type | Properties of Bilinear hysteric element in translation and rotation local X, Y, and Z directions (Kx, Ky ,Kz, Rx, Ry, and Rz). |
| Linear Stiffness Kx, Ky ,Kz, Rx, Ry, and Rz | Linear stiffness in translation and rotation local x, y & z directions of the isolator element. This stiffness is only used in linear and Eigen analysis. The local x direction is always considered perpendicular to the plane of the isolator. |
| Nonlinear Stiffness Kx, Ky ,Kz, Rx, Ry, and Rz | Nonlinear dynamic stiffness is defined in translation and rotation local x, y & z directions of the isolator element and is working only in nonlinear time history calculation. The local x direction is always considered perpendicular to the plane of the isolator. The stiffness in the x direction is compression only stiffness. |
| Yield Forces Pos-Fy(k), Neg-Fy (k) | The tension and compression yield forces of the isolator in the respective local direction. |
| Strain Hardening Ratio Alpha + Alpha - | The tension and compression ratios of post-yield stiffness to nonlinear dynamic stiffness of the isolator in the respective local direction. |
| Hyst. Rule |
Linear-Elastic Non-Elastic Isoperimetric-hardening |
