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376 Chapter 5: Creating Geometry
The parameters in this group box, available only
when End Point Method is set to Bound to Object
Pivots, specify how forces are applied by the
damper object in a dynamics simulation.
Damper Pa r ameter s —Provides parameters for a
damper t ype of object. Specifically, this simulates
a viscous linear damper, which provides linear
resistance to motion (between the two binding
objects) proportional to the rate at which the
damper experiences displacement. The faster it
gets hit, the harder it fights back. Push it slowly,
and there’s almost no resistance.
•
Object is Da mper—Select this option to use
the damper object as a damper rather than an
actuator.
Drag—Specifies the force per unit linear speed,
measured in one of t he methods specified below.
•
Drag is measured in—Lets you specify the
measurement of drag to use: Pounds per
in(ch)/sec or Newtons per m(eter)/sec.
•
Damper works in—Provides directional options
for the damper.
Co mpression Only—The damper reacts only to
compression forces.
Ex tensi on Only —The damper reacts only to
expansion forces.
Both—The damper reacts to both compression
and expansion forces.
Actuator Pa ra meters—Provides parameters for an
actuator.Whenusedasanactuator,thedamper
object exerts force between the two binding
objects. A real-world example might b e the
thrustingpistoninalogsplitter.Whenusedina
simulation, the force i s applied by adjusting the
valueintheForcespinner.Youcanseetheresult
only after solving the dynamics simulation.
•
Object is A ctuator—Choose this when using the
damper object as an Actuator.
Force —Specifies the amount of forc e exerted
between the two b ound objects. Positive values
push the objects ap art, while negative va lues pull
them together.
•
Force is measu red i n— Lets you specify the
measurement of force to use: Pounds per inch
or Newtons per meter.
Spr ing D yna mics Obj ect
Create panel > G eometr y > D ynamics Objects > O bject
Type rollout > Spring button
Create menu > Dynamics > Spring
TheSpringobjectisadynamicsobjectintheshape
of a coiled spring that lets you simulate a flexible
spring in dynamics simulations. You can specify
the overall diameter and leng th of the spring , the
number of turns, and the diameter and shape of its
“wire.” When used in a dynamics simulation, the
comp ression and extension pressure of the spring
are calculated as well.
Procedures
To create a spring:
1.
Drag and release to specify the outside
diameter.
2. Move the mouse and click to specify the over all
length of the spring.
To use a spring in a dy namics simulation:
Thefollowingmustbeinplacetousethespring
forces in a dynamics simulation:
1. Bind two objects to the ends of the spr ing, and
choose Bound to Object Pivots in the End Point
Method group box at the top of the command
panel.
2. In the dy namics simulation, add the spring
to the Object List. (The spring itself is not
adjustableinthedynamicsEditObjectdialog,