Fix Redundant Constraints With Revolute, Spherical, and Hooke Joint.
GUI Familiarity Level Required: Higher
Estimated Time Required: 10 minutes
MSC.ADAMS 2005 r2
1
Topics Covered
In this tutorial you will learn how to:
1.
Import .cmd file
2.
Add spherical joint
3.
Add hooke joint
4.
Fix redundant constraints
You will need to download the file “4-bar_redundant_constraint.cmd“ to begin this tutorial
If you have any difficulties, import the “4-bar_redundant_constraint_complete.cmd” file and proceed from pg 8
2
Fix Redundant Constraints Problem
As the model is defined, there are 3 redundant restraints. The use of different types of joints yield a
model with 0 DOF which allows for kinematics simulation while avoiding redundant constraints, which
is good modeling practice.
3
What You Should Accomplish
If you are successful you should end up with a
working ADAMS model that has no redundant
constraints.
4
Importing a command file (.cmd)
a.
Select Import a file radio button
b.
Click OK
a
b
File Import window will open
c.
Right-click File To Read text field, select Browse
d.
Locate saved file 4-bar_redundant_constraint
e.
Click Open
f.
Click OK
d
c
e
f
5
Add Spherical Joint
a.
Right-click on JOINT_2, select Joint: JOINT_2, select Delete
a
b.
c.
d.
Right-click Joint tool stack. Select Spherical joint
Set Construction text fields to 1 Location and Normal To Grid
Click PART_2.MARKER_2
d
b
c
6
Add Hooke Joint
a.
Delete JOINT_3
b.
Right-click Joint tool stack. Select Spherical joint
c.
Set Construction text fields to 1Location and Normal To Grid
d.
Click PART_3.MARKER_4
e.
Click on the cm (center of mass) of Part_2
f.
Click on the cm of PART_3
b
d
c
e
f
7
Verify
Verify your model. There should be 0 Degrees of Freedom and no redundant constraints
8
Model
This is what your screen should look like when
your model is complete
9
Topics Covered
In this tutorial, you learned how to:
1. Import .cmd file
2.
Add spherical joint
3.
Add hooke joint
4.
Fix redundant constraints
10
Best Practices
•
Check orientation of spherical joint
•
Check orientation of hooke joint, it should be along the cm of the two parts.
•
Remove unnecessary joints
•
Verify your model.
11