page 1 introduction to lagrange chapter 13 - seminar notes chapter 13 - rigids
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Page 3 Introduction to Lagrange Chapter 13 - RIGIDSMSC.Dytran Seminar Notes In MSC.Dytran arbitrary rigid bodies can be defined by: Arbitrary shaped rigid surfaces Rigid material Rigid Body Element RIGID BODY DEFINITIONTRANSCRIPT
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
CHAPTER 13 - RIGIDSCHAPTER 13 - RIGIDS
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
CONTENTS
• Rigid Body Definition
• Rigid Surfaces
• Rigid Material
• Rigid Body Loading
• Rigid Bodies Constraints
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
In MSC.Dytran arbitrary rigid bodies can be defined by:
• Arbitrary shaped rigid surfaces
• Rigid material
• Rigid Body Element
RIGID BODY DEFINITION
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
RIGID SURFACE - RIGID
• Rigid surface geometry defined by a arbitrary shaped multi-faceted surface
• Rigid surface properties must be defined by the user
- center of gravity
- mass
- moments of inertia
• Rigid surface initial velocity can be defined
Example: Rigid 25 which geometry is defined by surface 333, has a
mass of 200 kg, center of gravity is at (1., 1., 1.) and has
moments of inertia of 1.e5Initially the rigid surface has a velocity of 100
m/s in z-direction.SURFACE, 333,, PROP, 111
SET1, 111, 222
RIGID, 25, 333, 200.,, 1., 1., 1.,, +
+,,,, 100.,,,,, +
+,,1E5,1.E5,1.E5,1.E5,1E5,1E5
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
RIGID MATERIAL - MATRIG
• Material treated as one rigid element
No matter how many elements and properties are used to make up the rigid body, in the solution it is treated as a single element They are very cheap to use
Name will become: MR<material number>
• MATRIG properties can be defined by the user
Normally, the user would simply replace a material entry like DMATEP by MATRIG, after which MSC.Dytran calculates the geometric properties of the rigid body from the density or mass and geometry
The user can also supply center of gravity, mass, moments of inertia and initial velocities himself
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
RIGID MATERIAL - MATRIG(Continued)
Example: Rigid material number 19 which properties like mass,
center of gravity and moments of inertia are calculated
by MSC.Dytran
MATRIG, 19, 7850.
Name will become: MR19
Example: Rigid material number 200 with initial velocity of 10
in x-direction and of which the mass is 1000., center of
gravity is at (0., 7., -3.1) and also the moments of inertia
are supplied by the user
MATRIG, 200, , 210.E9, 0.3, 1000., 0.0, 7.0, -3.1, +
+ , 17.0, 13.2, 14.3, 0., 0., 10., , , +
+ , 10., 0., 0., 0., 0., 0.
Name will become: MR200
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
RIGID BODY ELEMENT - RBE2-FULLRIG
• Defines a set of grid points that form a rigid body
This entry allows particular degrees of freedom of a set of grid points to be tied together so that they always move the same amount
Properties of rigid body will be calculated by MSC.Dytran based upon the masses associated with the grid points that are part of the RBE2-FULLRIG
Name will become: FR<material number>
Example: Nodes 1 to 28 and 55 will behave like a rigid body
RBE,12,55,FULLRIG,1,THRU,28
The name will be FR12
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
Prescribes transient dynamic loading
TYPE = 13 in TLOAD1 definition
Must be selected in Case Control
Any loading (TLOADn entry) not selected in Case Control is ignored
Loading acts on the center of gravity of the rigid body
RIGID BODY LOADING
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
RIGID BODY LOADING(Continued)
Example: Force on rigid material 19 varying in time
TLOAD = 1
BEGIN BULK
...
MATRIG, 19, 7850.
TLOAD1, 1, 444, , 13, 12
FORCE, 444, MR19,, 100., 0., 0., 1.
TABLED1, 12, , , , , , , , +
+, 0.0, 0.0, 1.0, 1.0, ENDT
Example: Force on rigid surface 19
TLOAD = 1
BEGIN BULK
...
RIGID, 19, 333, 200.,, 1., 1., 1.,, +
+,,,, 100.,,,,, +
+,,1E5,1.E5,1.E5,1.E5,1E5,1E5
TLOAD1, 1, 444, , 13
FORCE, 444, 19,, 100., 0., 0., 1.
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
Example: Force and moment on a FULLRIG-RBE2 19
TLOAD = 1
BEGIN BULK
...
RBE,19,55,FULLRIG,1,THRU,28
TLOAD1, 1, 444, , 13
FORCE, 444, FR19,, 100., 0., 0., 1.
MOMENT, 444, FR19,, 100., -1., 0., 0.
RIGID BODY LOADING(Continued)
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
Prescribes transient dynamic velocity field
TYPE = 12 in TLOAD1 definition
Must be selected in Case Control
Any loading (TLOADn entry) not selected in Case Control is ignored
The center of gravity of the rigid body will be constraint
RIGID BODY CONSTRAINTS
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
RIGID BODY CONSTRAINTS(Continued)
Example: Z-velocity of a rigid material 19 varying in time
Allow body to move freely in x and y-direction
TLOAD = 1
BEGIN BULK
...
MATRIG, 19, 7850.
TLOAD1, 1, 444, , 12, 13
FORCE, 444, MR19, ,100., , , 1.
TABLED1, 12, , , , , , , , +
+, 0.0, 0.0, 1.0, 1.0, ENDT
Blanks!!!
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Introduction to Lagrange
Chapter 13 - RIGIDS MSC.Dytran Seminar Notes
RIGID BODY CONSTRAINTS(Continued)
Example: Constrain rigid body MR19 to move in any direction
TLOAD = 1
BEGIN BULK
...
MATRIG, 19, 7850.
TLOAD1, 1, 54, , 12
FORCE, 54, MR19, , 0., 1., 1., 1.
MOMENT, 54, MR19, , 0., 1., 1., 1.