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Innovation Intelligence®
Section 19
Bolt Modeling
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Bolt Modeling workbench
• Application | Special | Bolt Modeling
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Bolt - Head
• A bolt is modeled as 2 parts, the head and the tail. The head portion can be modeled in
one of several ways. Most common type is top and bottom RBE connected by a bar
element.
T o p R B E
B o t t o m R B E
B a r
T o p R B E
B a r
B o t t o m R B E
B a r
T o p R B E
B o t t o m R B E
B a r
Mid RBE B a r
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Edge Based Bolt-Head (Ex:Cover.gda)
• To create the head part of the bolt hole, the bolt holes are identified by manually by
selecting the single edge on top and bottom of the holes. Multiple bolts can also be
created by selecting top and bottom edges for each bolt hole.
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Edge Based Bolt-Head (Contd.)
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Face Based Bolt-Head (Ex:Cover.gda)
• It is possible that a model can have a lot of bolts and it makes it difficult to manually
pick all the edges. So the another option is provided to model bolt heads on all the hoes
on a face. User need to select the face(s) where bolt head sits and specify the bolt hole
diameter range.
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Face Based Bolt-Head (Contd.)
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Bolt - Thread
• The thread portion of the bolt can be modeled in one of several ways.
B o t t o m R B E
T o p R B E
B o t t o m R B E
B a r
B o t t o m R B E
B a r
T o p R B E
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Configuration of bottom RBE
• Down
• Up
• Both
• Sections
D o w n S e c t I o n s
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Edge Based Bolt-Thread (Ex:Carrier.gda)
• To create the thread part of the bolt hole, the bolt holes are identified by manually
selecting the single edge on top of the holes. Multiple bolts can also be created by
selecting top edges for each bolt hole.
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Edge Based Bolt-Thread (Contd.)
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Edge Based Bolt-Thread (Contd.)
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Face Based Bolt-Thread (Ex:Carrier.gda)
• User need to select the face(s) and specify the bolt hole diameter range.
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
File based bolt modeling (Ex: Diff_Case.gda)
• Bolt Modeling | Import Bolt
• Bolts can also be modeled by directly importing the bolt definition file. Importing bolt will
create both head and thread portion of bolts. There are three different blocks in the file
called BOLT, HEAD_DEF and THREAD_DEF define bolt, head and thread
respectively. The complete definition for each key work of the bolt definition file is
available in F1 help.
• Sample bolt definition file (BoltDefinition.dat).
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Bar Pretension
• Bolt Modeling | Bar Pretension
• User can model the pre tension in the tightened bolt in several ways. The tension in the
tightened bolt is modeled by creating RBEs, Bars and force by selecting the edges on
bolt hole. This option is referred as “Edge Based”.
• Different types of Bar Pretension are
• Through
• Threaded
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Through / Threaded (Edge Based)
T o p R B E
B o t t o m R B E
B a r
F o r c e
T o p R B E
B o t t o m R B E
B a r
F o r c e
T o p R B E
B o t t o m R B E
B a r
F o r c e
T o p R B E
B o t t o m R B E
B a r
F o r c e
B a r
T o p R B E
B o t t o m R B E
F o r c e
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Through (Ex: BarPretension.gda)
• This type can be modeled by selecting the top edge of bolt shank hole and bottom edge
of threaded hole.
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Through (Contd.)
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Threaded (Ex: BarPretension.gda)
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
RBE Based (Ex:RBEBased_BarPretension.gda)
• Bar pretension can also be modeled by directly selecting the RBEs/Nodes referred as
“RBE Based” and “Node Based” respectively.
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Node Based (Ex:RBEBased_BarPretension.gda)
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Solid Pretension
• Bolt Modeling | Solid Pretension
• User can model the pre tension in the tightened bolt by applying solid pretension for the
following solver,
• Abaqus
• Ansys
• Nastran
• Permas
• There are three ways of creating Abaqus bolt,
• Creating pretension face
• Using existing pretension face
• Find pretension face
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Abaqus – Creating pretension cut
• Ex: Bolt.gda
• Define the plane where to create the pretension cut.
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Abaqus – Using existing pretension cut
• Ex: Bolt_With_Cut.gda
• Select the pretension cut face in the bolt
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Ansys, Nastran, Permas solid pretension
1. There are three ways of creating Ansys, Nastran and Permas bolt
1. Creating pretension cut
2. Using existing pretension cut
3. Using the faces apart in the bolt
2. Creating pretension cut (Ex: Bolt.gda)
• User need to define the plane to create pretension cut and solid pretension
based on solver.
3. Using existing pretension cut (Ex: Bolt_With_Cut.gda)
• User need to select the existing pretension cut to create solid pretension based
on solver.
4. Using the faces apart in the bolt (Ex: Bolt_With_Face_Apart.gda)
• User need to select the two face apart in the bolt to create solid pretension
based on solver.
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Bolt.gda, Bolt_With_Cut.gda, Bolt_With_Face_Apart.gda
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Solid Bolt
• Bolt Modeling | Solid Bolt
• User need to define the axis and
pivot point followed by the parameters.
• Templates can be exported/imported.
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Solid bolt patterns
Pattern 1 Pattern 2 Pattern 3 Pattern 4
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Connection
• Bolt Modeling | Connection
• Creates connection between bodies automatically.
• Rigid Bar
• Equivalence
• RBE
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Rigid Bar (Ex: Connection.gda)
• Bolt Modeling | Connection | RBAR
• User can select either the option between two bodies (Rigid body/Bar body) or all
bodies to connect the free nodes by RBAR by identifying the matching nodes based on
the tolerance value specified.
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Rigid Bar (Contd.)
RBAR
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Equivalence (Ex: Connection.gda)
• Bolt Modeling | Connection | Equivalence
• RBE center nodes and bar body free nodes, which lie within the given tolerance will get
equivalence.
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Equivalence (Contd.)
Node equivalence
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RBE (Ex: Connection.gda)
• Bolt Modeling | Connection | RBE
• User need to select dependent and independent body, based on the tolerance specified
the matching nodes will be connected by a RBE.
Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
RBE (Contd.)
Dependent body
Independent body
Connecting RBE
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