Deactivate

Command ElementSwitches off a formerly activated model element. The modeling element is ignored in all subsequent analyses, unless it is explicitly "activated."

Format

<Deactivate
    element_type    = "string"
    element_id      = "integer"
/>

Attributes

element_type
Specifies the type of the element to be deactivated. See Comment 1 for valid element types.
element_id
Specifies the ID of the element to be deactivated.

Example

<Deactivate
     element_type = "JOINT"
     element_id   = "301002"
 />

Comments

  1. The element_type must be one of the following keywords:
    Keyword
    Corresponding model element(s)
    "BEAM"
    Force_Beam
    "BUSH"
    Force_Bushing
    "CONTACT"
    Force_Contact
    "COUPLER"
    Constraint_Coupler
    "CVCV"
    Constraint_CVCV
    "CVSF"
    Constraint_CVSF
    "DIFF"
    Control_Diff
    "FIELD"
    Force_Field
    "FORCE"
    All action forces.
    "FRICTION"
    Force_JointFriction
    "GCON"
    Constraint_General
    "GEAR"
    Constraint_Gear
    "GFORCE"
    Force_Vector_[One|Two]Body - Force and torque
    "GSE"
    Control_StateEqn - of type USERSUB
    "JOINT"
    Constraint_Joint
    "JPRIM"
    Constraint_Jprim
    "LSE"
    Control_StateEqn - of type LINEAR
    "MATE"
    Constraint_Mate
    "MFORCE"
    Force_FlexModal
    "MOTION"
    Motion_Joint or Motion_Marker
    "NFORCE"
    Force_MultiPoint
    "PFORCE"
    Force_Penalty
    "PTCV"
    Constraint_PTCV
    "PTDCV"
    Constraint_PTdCV
    "PTDSF"
    Constraint_PTdSF
    "PTDSFF"
    Force_PTdSF
    "PTSF"
    Constraint_PTSF
    "SENSOR"
    Sensor_Event or Sensor_Proximity
    "SFORCE"
    Force_Scalar_[One|Two]Body - Force or Torque
    "SFSF"
    Constraint_SFSF
    "SPDP"
    Force_SpringDamper
    "TFSISO"
    Control_SISO
    "UCON"
    Constraint_UserConstr
    "VFORCE"
    Force_Vector_[One|Two]Body - Force only
    "VTORQUE"
    Force_Vector_[One|Two]Body - Torque only
    "YFORCE"
    Force_StateEqn
  2. Constraints such as joints (Constraint_Joint) and joint primitives (Constraint_Jprim) are frequently used to “temporarily” constrain a system such an automobile, so that static equilibrium can be more easily found. In this scenario, the system has a neutral equilibrium position - the automobile can come to equilibrium anywhere in the X-Y plan that represents the ground. Once the static equilibrium is completed, the constraint element is “deactivated” prior to dynamic analysis.
  3. The Deactivate command may also be used to simulate the “breaking” of a rigid body. A rigid body is defined as an assembly of two rigid bodies connected together with a fixed joint. As long as the fixed joint is active, the two bodies behave together like one body.

    The forces in the fixed joint may be monitored, and when they reach a critical value, the fracture value (the fixed joint) is deactivated. This allows the two rigid bodies that comprise the original single body to move independently.

  4. Deactivate in conjunction with Activate may be used to change the topology of the model during a simulation. For instance, solar panels in a spacecraft are always stored in a stowed position during takeoff. Once in space, bolts holding the panels together are deactivated. This removes the restraint on the panels, and causes them to deploy.
  5. You can also deactivate a formerly activated model element by using the following user subroutine: MODSET("element_type", id, "deactivate", "TRUE").