GTSTRUDL User’s Group
Annual Meeting - 2011
BASE PLATE ANALYSIS
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June 23, 2011
Parimal Gandhi, PE
Sr. Engineer
PURPOSE
Non-Linear Finite Element Analysis For Base Plate.
AND
Stiffness Analysis For Base Plate.
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AGENDA
1. INTRODUCTION AND THEORY
2. BASE PLATE MODELING
3. EDIT THE BASE PLATE INPUT FILE
4. BASE PLATE STRESSES & BOLTS LOADS
5. FLEXIBLE & RIGID BASE PLATE RESULTS
6. CONCLUSION
3
Introduction & Theory
The finite element method is used to analyze the base
plate considering the beam on elastic foundation.
The concrete and bolts are represented by non linear
spring elements attached to the nodal points on the steel
base plate and to the ground.
The steel base plate is modeled with SBHQ6
and SBHT6 plate bending element.
Attachments and Stiffeners are modeled as RIGID
SOLIDS in the plane of the base plate.
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Introduction & Theory
5
The Beam on Elastic Foundation
Introduction & Theory
Non Linear Spring Element
Concrete
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Introduction & Theory
Non Linear Spring Element
Bolt
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Introduction & Theory
Non-linear Spring Curves
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Base Plate Modeling
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Base Plate Modeling
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Circular Base Plate Modeling
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Circular Base Plate Modeling
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Circular Base Plate Modeling
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Circular Base Plate Modeling
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Circular Base Plate Modeling
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Circular Base Plate Modeling
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Circular Base Plate Modeling
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Circular Base Plate Modeling
Elements=24x12=288
Joints=289
Joint 289
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Element 288
Edit Base Plate Input File
The GT Model Wizard creates a GTSTRUDL input file that remains after the
Wizard is closed.
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Edit Base Plate Input File
Soil Spring Values
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Edit Base Plate Input File
For Attachment
Master Joint
‘C1’
Slave Joints
74 to 97
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Edit Base Plate Input File
For Concrete Stiffness
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Edit Base Plate Input File
For Concrete Stiffness
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Edit Base Plate Input File
For Bolt Stiffness
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Edit Base Plate Input File
For Bolt Stiffness
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Edit Base Plate Input File
LOADING
Non Linear
Analysis
Output
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Base Plate Stresses
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Bolt Support Reactions
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Square /Rectangular Base Plate Modeling
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Square /Rectangular Base Plate Modeling
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Square /Rectangular Base Plate Modeling
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Square /Rectangular Base Plate Modeling
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Square /Rectangular
Base Plate odeling
Base Plate Modeling
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Square /Rectangular Base Plate Modeling
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Square /Rectangular Base Plate Modeling
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Square /Rectangular Base Plate Modeling
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Square Base
/Rectangular
Plate Modeling
Base Plate Modeling
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Square /Rectangular Base Plate Modeling
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Square /Rectangular Base Plate Modeling
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Square /Rectangular Base Plate Modeling
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Square /Rectangular Base Plate Modeling
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Square /Rectangular Base Plate Modeling
X
Total Joints =169
Total Elements =144
z
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Square /Rectangular Base Plate Modeling
Master Joint
‘C1’
Spring Element
‘S1’
Spring Element
‘S169’
Slave Joints
57, 61 … 113
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Edit Base Plate Input File
LOADING
Non Linear
Analysis
``
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Output
Square /Rectangular Base Plate Stresses
B3
B1
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B4
B2
Support Reactions for Bolts
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Edit Rigid Base Plate Input File
Rigid Attachment
Bolt : Pinned Support
``
``
Loading
Stiffness Analysis
Output
``
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Flexible & Rigid Base Plate Result
Flexible
Non-Linear
Base Plate Analysis
With Concrete & Bolt
Stiffness
Maximum Bolt Pull
out
Maximum Shear Load
Base Plate Stresses
Base Plate
Displacement
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Rigid
Linear/Stiffness
Base Plate Analysis
Without Concrete & Bolt
Stiffness
339 lbs
423 lbs
949 lbs
949 lbs
9215 psi
9404 psi
Δy=0.00361”
Δy=0.00432”
Questions?
Thank you.
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