Whole-Blade Damping

Bladed is able to introduce modal damping by applying a damping ratio for each whole-blade mode. The user can choose how many whole-blade modes to specify damping ratios for using the WholeBladeModeDampingRatios array. Any higher frequency modes will be assigned frequency proportional damping, based on the damping of the highest mode with damping defined. This approach applies high damping to high frequency modes and effectively excludes the higher whole-blade modes from the blade dynamic response, so that they do not cause erroneous instability. See the theory section description of blade damping for more details. Note that Bladed will then automatically calculate the damping values to assign to each individual blade part (see multi-part blade definition).

Note

The user can add any metadata adjacent to the damping values, such as "_Name" or "_Mode". Bladed will ignore it so long as it is preceded by an underscore.

Example of the definition of the first seven whole-blade modes:

"WholeBladeModeDampingRatios": [
  {
    "DampingRatio": 0.0048
  },
  {
    "DampingRatio": 0.0048
  },
  {
    "DampingRatio": 0.0048
  },
  {
    "DampingRatio": 0.0048
  },
  {
    "DampingRatio": 0.0048
  },
  {
    "DampingRatio": 0.0048
  },
  {
    "DampingRatio": 0.0095
  }
],