Physical Dynamics is an option in Collision Detection that allows you
to see the motion of assembly components in a realistic way.
With Physical Dynamics enabled, when you drag a component, the component
applies a force to components that it touches. The effect is to move or
rotate contacted components within their allowable degrees of freedom.
The dragged component reacts to a collision by rotating within its allowable
degrees of freedom or by sliding against a constrained or partially constrained
component to allow the drag to continue.
Physical Dynamics propagates throughout the assembly. The dragged component
can push aside a component, which then moves into and pushes aside another
component, and so on.
Physical Dynamics works best and is most
meaningful on assemblies that have only a few degrees of freedom. Add
all appropriate mates prior to running Physical Dynamics.
You cannot use Physical Dynamics and Dynamic Clearance at the same time.
To move a component using physical dynamics:
Click Move Component
or Rotate Component
on the Assembly toolbar.
In the PropertyManager, under Options,
select Physical Dynamics.
Move the Sensitivity slider
to change the frequency with which Physical Dynamics checks for collisions.
Move the slider to the right to increase the sensitivity. At the most
sensitive setting, the software checks for collisions every .02mm (in
model units). At the least sensitive setting, the check interval is 20mm.
Use the most sensitive settings only
for very small components, or for components with complex geometry in
the collision area. When you use the maximum sensitivity when checking
for collisions between larger components, the drag is very slow. Use only
the sensitivity setting you need to see the motion in your assembly.
If needed, specify the components to participate
in the collision:
Select components for Components
for Collision Check.
Click Resume Drag.
Choosing specific components in Collision
Detection improves the performance of Physical Dynamics. Choose only those
components that are directly involved in the motion you are testing.
Dragged part only to check for
collisions with only the components that you selected to move. When cleared,
the components that you selected to move, plus any other components that
move because of mates with the selected components, are checked.
Drag a component in the graphics area.
When Physical Dynamics detects a collision it adds a contact force
between the colliding parts and allows the drag to continue. The force
remains as long as the two parts touch. When the two parts no longer touch,
the force is removed.
You can select one component after another within a single command.
If the component you drag has an initial collision with another component,
SolidWorks displays a message in the graphics area and all components
involved in the collision turn transparent. Physical Dynamics is turned
off for collisions between the transparent components. You can continue
the drag, and collide with and apply a force to other components.
To activate a collision between initially colliding
Drag your component until it no longer interferes.
Release the drag.
The components are no longer transparent, and Physical Dynamics
Dragging by Center of Mass
When you click a component to drag it, a center of mass symbol appears at the component's center of mass. If you click the
symbol and drag the component, you are dragging by the center of mass.
If you click outside the symbol and drag, you are dragging by the point
on the body you clicked.
You apply a moment arm to a component if you drag outside the center
of mass, which causes the component to rotate within the allowable degrees
NOTE: The center of mass symbol
appears during Move, but not during Rotate. The Free
Drag option in Rotate Component
is by definition rotation about the center of mass.