light truck frame joint toolkit phase 3 - autosteel/media/files/autosteel/great designs in...
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LIGHT TRUCK FRAME JOINT TOOLKITPHASE 3
Arun KumarAltair Engineering
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Light Truck Frame Joint Study Objective
To develop design rules that will facilitate the design of lighter weight steel frames.
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• Literature Search• Finite Element Analysis• Physical Testing• Design Sensitivity• Design Rules Development
ORIGINAL PROJECT
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• Fore/Aft Load: Mzθz
JOINT STIFFNESS TEST
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• Vertical Load: Mxθx
JOINT STIFFNESS TEST
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• Torsional Load: Myθy
JOINT STIFFNESS TEST
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STIFFNESS CALCULATIONS
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TYPICAL JOINTS
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TEST FIXTURE
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SAMPLE JOINT
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Joint 5 Fore/Aft LoadingSection 3 Test Deflection
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
-300 -200 -100 0 100 200 300
Load (N)
Defle
ctio
n (m
m)
J5_S3_run1J5_S3_run2J5_S3_run3
TEST REPEATIBILITY
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Joint 5 Fore/Aft LoadingHi/Lo Test vs. Analysis Joint Deflections
-1.5
-1
-0.5
0
0.5
1
1.5
-300 -200 -100 0 100 200 300
Load (N)
Defle
ctio
n (m
m)
J5_S1_run1J5_S3_run1Analysis
K = 0.49 KNmm/degree
K =0.51 KNmm/degree
a
t
CORRELATION
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• Design Variables– Component Gage
• Cross Member• Inner Side Rail• Outer Side Rail
– Shape Variables• Cross Member Weld Flange Width• Cross Member Upper Flange Width• Cross Member Height• Cross Member Width• Rail Height• Rail Width
TYPICAL JOINT PARAMETERS
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DESIGN VARIABLES
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DESIGN VARIABLES
CROSSMEMBER WIDTH ANIMATION
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Mzθz
C r o s sM e m b e rT h i c k n e s s
I n n e r R a i lT h i c k n e s s
O u t e rR a i lT h i c k n e s s
C r o s sM e m b e rW e ldF la n g eW i d t h
C r o s sM e m b e rU p p e rF la n g eW i d t h
C r o s sM e m b e rH e i g h t
C r o s sM e m b e rW i d t h
S i d e R a i lH e i g h t
S i d e R a i lW i d t h
JOINT SENSITIVITY PLOTS
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Joint #1 Stiffness CalculationsInputs
Value Max MinTube Dia 75 50 100Tube Gage 3 2 4Rail Height 125 75 150Rail Width 75 50 100Rail Gage 3 2 4
Outputs
Bending Stiffness xxx KN-m/degTorsion Stiffness yyy KN-m/degFore/Aft Stiffness zzz KN-m/deg
JOINT STIFFNESS CALCULATIONS
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Summary• Study of frame joints.• Identify key joint characteristics.• Capture design rules and sensitivities.• Present in format for frame designers.• Push knowledge into the concept stage.• Reduce weight.• Unique study.
PHASE 1 & 2 SUMMARY
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• Recent Additions– Total of 16 Joints– Optimization for all 16 joints
PHASE 3 WORK
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• 2 New Joints
ADDITIONAL JOINTS
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• Optimization– Set target stiffnesses– Define Ranges for the design variables– Optimization finds the minimum mass joint that
meets all stiffness criteria– Requires Excel 2002
OPTIMIZATION OF JOINTS
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• Optimization Panel
OPTIMIZATION OF JOINTS
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• Optimization Panel
OPTIMIZATION OF JOINTS
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• Optimization Panel
OPTIMIZATION OF JOINTS
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• Optimization Panel
OPTIMIZATION OF JOINTS
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• Optimization Panel
OPTIMIZATION OF JOINTS
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• Most Light Truck Frame Joints available• Optimization of stiffness now available• Easy to use Excel format• Facilitates Early Design Decisions • CD available today or download from the
Auto-Steel Partnership website
SUMMARY