Alibre Design

Chapter 19 - Alibre Motion‣ To Re-Name, Delete, or Suppress an Actuator:1. Right-click the Actuator in the Motion Explorer, and select the required option.Suppressed Actuators are shown greyed out.Force- and Torque- Type ActuatorsIn many circumstances, simulations using these types can be the more realistic choice.Actuators of these types may be opposed by springs, dampers, and the inertias of anydriven parts in a realistic way.Forces and Torques can be defined in the following ways:• Constant Force or Torque• Harmonic (or Sinusoidally varying) Force or TorquePrescribed Motions and RotationsActuators of the Prescribed-Motion type produce the specified motion of the connectedparts, no matter what magnitude of force or torque would be required to do so in thereal world. They are very useful for answering sizing questions like: “Assuming this partis to rotate at 5rpm, what torque would be required?”, and are often used for modellingsub-sections of larger systems where the required output of the system is specified inadvance, and for examining the ranges of motion of parts.Prescribed Motions can be defined in the following ways:• Constant Motion• Harmonic Motion (or Sinusoidal Motion)Some characteristics of Prescribed Motions and Rotations• Prescribed Motion Actuators are Incompatible With Springs and DampersSince Springs and Dampers produce force or torque effects, any PrescribedMotions acting on the same constraints will completely override them. In thissituation, any Springs or Dampers will be automatically excluded from thesimulation (Springs and Dampers on other constraints remain unaffected, andtheir effects will be calculated normally).• Prescribed Motion Actuators Can Produce Locking539