Viscous branch definition

@VISCOUS_BRANCH_DEFINITION {
@VISCOUS_BRANCH_NAME {EldVscName} {
@MAXWELL_FLUID_BRANCH {
@STIFFNESS_COEFFICIENT {kv}
@RELAXATION_TIME {τ}
}
@HOFER_LION_BRANCH {
@STIFFNESS_COEFFICIENT {kv}
@MATERIAL_CONSTANT_TAU0 {τ0}
@MATERIAL_CONSTANT_DI {d1, ..., dn}
@MATERIAL_CONSTANT_TAU_QI {τq1, ..., τqn}
}
@HAUPT_SEDLAN_BRANCH {
@STIFFNESS_COEFFICIENT {kv}
@MATERIAL_CONSTANT_ZMAX {zmax}
@MATERIAL_CONSTANT_ZMIN {zmin}
@MATERIAL_CONSTANT_ZQ {zq}
@MATERIAL_CONSTANT_ZETA {ζ}
@MATERIAL_CONSTANT_XI {ξ}
}
@COMMENTS {CommentText}
}
}

Introduction

Figure 1. Configuration of the plastic branch.

The viscous branch, shown in fig. 1, is a component of an elastomeric damper model. It features an elastic spring of stiffness constant kv and a viscous element. Three models are available to describe the viscous behavior of the system. The models are mutually exclusive and are introduced by one of the following three keywords.

  1. @MAXWELL_FLUID_PARAMETERS: the viscous branch is a Maxwell fluid element.
  2. @HOFER_LION_PARAMETERS: the viscous branch is described by the simplified Höfer-Lion model.
  3. @HAUPT_SEDLAN_PARAMETERS: the viscous branch is described by the Haupt-Sedlan model.

NOTES

  1. All three models require the definition of the stiffness coefficient, kv.
  2. When defining the Höfer-Lion model, material constant τ0 must be defined. Materials constant di and τqi are defined in pairs and an equal number of them must be defined. If all di = 0 and τqi = 0, the model degenerates and becomes identical to the Maxwell fluid model. (Default values: di = 0,τqi = 0.)
  3. When defining the Haupt-Sedlan model, material constant zmax, zmin, and zq must be defined. If ζ = 0 the model degenerates and the internal state becomes a constant, z = zmax. If both ζ = 0 and ξ = 0 the model further degenerates and becomes identical to the Maxwell fluid model. (Default values: ζ = 0, ξ = 0.)
  4. It is possible to attach comments to the definition of the object; these comments have no effect on its definition.