How To: Internal Conditions

Internal conditions are defined in the internal_conditions array:

{
  "internal_conditions": [ ]
}

Body loads comprise forces that are distributed over a solid volume.

Linear Acceleration Load or Gravity

A linear acceleration load can be used to simulate the effect of gravity. The material in the body will tend to be pulled in the direction of the acceleration vector. A linear acceleration body load is configured by specifying the direction of the acceleration and its magnitude.

The inputs to the body load are:

  • the direction vector of the acceleration field

  • the units that apply to the magnitude

  • the magnitude of acceleration

{
  "direction": [0, 0, -1],
  "magnitude": 9.80665,
  "type": "body_load",
  "units": "MeterKilogramSecond"
}

Rotational Load

Rotational body loads simulate the effect of a body rotating around an axis. Two contributions are considered in a rotational body load: angular velocity and angular acceleration. The angular velocity term simulates the centrifugal effects that tend to throw a body’s material away from the axis of rotation. The angular acceleration term simulates the effect of a rotational acceleration field around the axis of rotation. A positive angular acceleration tends to drag the body’s material in the positive rotational direction according to the right-hand rule.

A rotational body load has inputs:

  • origin point for the axis of rotation

  • vector defining the axis of rotation

  • angular_velocity (in radians/sec)

  • angular_acceleration (in radians/sec²)

{
  "origin": [0, 0, 0],
  "axis": [0, 1, 0],
  "angular_velocity": 10,
  "angular_acceleration": 0.5,
  "type": "rotational_load"
}

Thermal Body Loads

Constant Heat

A “Constant Heat” or body heat flux load applies uniform heat generation over a specified volume.

Constant heat flux has inputs:

  • the instance_id of the components which are producing heat flux

  • the magnitude of the body heat flux

  • the units (default MKS)

{
  "instance_id": "beam",
  "magnitude": -200000.0,
  "type": "constant_heat",
  "units": "MeterKilogramSecond"
}