4.13.5.28. KikuchiAikenHDR Material¶

uniaxialMaterial('KikuchiAikenHDR', matTag, tp, ar, hr, <'-coGHU', cg, ch, cu>, <'-coMSS', rs, rf>)

This command is used to construct a uniaxial KikuchiAikenHDR material object. This material model produces nonlinear hysteretic curves of high damping rubber bearings (HDRs).

 matTag (int) integer tag identifying material tp (str) rubber type (see note 1) ar (float) area of rubber [unit: m^2] (see note 2) hr (float) total thickness of rubber [unit: m] (see note 2) cg ch cu (float) correction coefficients for equivalent shear modulus (cg), equivalent viscous daming ratio (ch), ratio of shear force at zero displacement (cu). rs rf (float) reduction rate for stiffness (rs) and force (rf) (see note 3)

Note

1. Following rubber types for tp are available:
• 'X0.6' Bridgestone X0.6, standard compressive stress, up to 400% shear strain
• 'X0.6-0MPa' Bridgestone X0.6, zero compressive stress, up to 400% shear strain
• 'X0.4' Bridgestone X0.4, standard compressive stress, up to 400% shear strain
• 'X0.4-0MPa' Bridgestone X0.4, zero compressive stress, up to 400% shear strain
• 'X0.3' Bridgestone X0.3, standard compressive stress, up to 400% shear strain
• 'X0.3-0MPa' Bridgestone X0.3, zero compressive stress, up to 400% shear strain
2. This material uses SI unit in calculation formula. ar and hr must be converted into [m^2] and [m], respectively.
3. rs and rf are　available if this material is applied to multipleShearSpring (MSS) element. Recommended values are rs = $$\frac{1}{\sum_{i=0}^{n-1}\sin(\pi*i/n)^2}$$ and rf = $$\frac{1}{\sum_{i=0}^{n-1}\sin(\pi*i/n)}$$, where n is the number of springs in the MSS. For example, when n=8, rs =0.2500, rf =0.1989.