A helical spring, or a coil spring, is a member that stores energy and subsequently
releases it. A helical spring is used in various applications like: automobile suspensions,
engine valves, measuring scales, box springs, etc. An NLFE helical spring system is a
MotionView system definition that can be used to represent a spring as
a non-linear finite element body.
A helical spring needs the following entities to be present in the model:
- Body 1 attachment - The body to which the spring will be attached at one
end.
- Body 2 attachment - The body to which the spring will be attached at the
other end.
- Point 1 attachment - Spring center point at the Body 1 attachment end which
will be used to interface the spring with Body 1 attachment.
- Point 2 attachment - Spring center point at the Body 2 attachment that will
be used to interface the spring with Body 2 attachment.
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From the Subsystems toolbar, click the NLFE Helical Spring
Subsystem toolbar icon
.
The Add an NLFEHelicalSpring Subsystem dialog is
displayed.
-
Click the System collector and decide which system the
spring needs to be created in.
-
Specify a variable name and label for the spring.
By default, variable names of entities in MotionView follow a
certain convention. For example, all NLFE helical spring entities have a
variable name starting with nlfehs_. This is the recommended
convention to follow when building models in MotionView since
it has many advantages in model editing and model manipulation.
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Double-click the MaterialProperty collector and select a
material to define the spring, or accept Steel as the default.
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Click the Body 1 collector and select the attaching body
at end 1 from the modeling window, or double-click the
collector to display the Model Tree (from which the
desired body can be selected).
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In the same manner, use the Point 1 collector to select
the attaching point at end 1 corresponding to Body 1.
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Select the attaching body at end 2 and the corresponding point with the
Body 2 and Point 2
collectors.
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Enter values for Wire diameter, Spring
diameter, Num of active coils, and
Num of inactive coils.
-
Click OK.
The helical spring system that is created has the following
architecture:
| Entity |
Description |
| Body |
A large deformation entity for the spring is
created. |
| DataSet |
A dataset where editable values are populated. After the
creation of the helical spring, you can change the
parameters like spring diameter and wire diameter from this
dataset. |
| Markers |
A bottom and a top marker are created at the spring
centers. |
| Points |
The points that define the spring profile are defined in
the cylindrical coordinates system with respect to the
marker at the spring bottom. The point and hence the entire
spring position and orientations are governed by this
marker. |
| Template |
The helical spring that is created has coil-to-coil
contact elements. This contact is modeled using a NLFE
spring-damper entity called a LINE2 element. These elements
are not supported in MotionView and hence
are added in the form of a template. |
Tip:
- Activate Show additional parameters to specify
variable names and labels for the points that are to be created. You can
also edit the element density per coil of the spring coils.
- To return to default settings, click Reset to
Defaults.