General Motors Tutor Presentation : Peter Foss Project Supervisor : Professor Ahmad Barari Faculty...
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DESIGN AND ANALYSIS OF THE AUTO BODY DOORS OF THE GENERAL MOTORS CHEVROLET .RU General Motors Tutor Presentation : Peter Foss Project Supervisor : Professor Ahmad Barari Faculty of Engineering & Applied Science University of Ontario Institute of Technology Ahmad.barari@uo it.ca
General Motors Tutor Presentation : Peter Foss Project Supervisor : Professor Ahmad Barari Faculty of Engineering & Applied Science University of Ontario
General Motors Tutor Presentation : Peter Foss Project
Supervisor : Professor Ahmad Barari Faculty of Engineering &
Applied Science University of Ontario Institute of Technology
[email protected]
Slide 2
Team members: Gregory Eberle, B.Eng (Team Leader)
[email protected] Stephan Cregg, B.Eng Guarav Sharma, B.Eng
Slide 3
Material choice Composites Fibre Characteristics Fibre
Selection: E-glass Fibre Orientation : Random Fibre volume ratio:
25% outer door panel (Grade A SMC) 40% inner door panel (Structural
SMC) Critical fibre length: 0.8625 mm Chosen fibre length: 25 mm
(over 30 times l c ) Fibre diameter = 15 microns (between 20-150
times smaller than l c )
Door Auto Body CAD Design Front Door Butterfly Hinges Original
Equipment Manufacturers (OEM) Hinges Impact Beam 15 from the
horizontal
Slide 6
Finite Element Models Frame Rigidity Test Vertical Displacement
Test Geometry #1 Geometry #2 CAD model use for FEA Used portion of
door to eliminate computational shortfalls 2 ribbing geometries
test based on various quantities
Slide 7
Finite Element Analysis Results Steel = 3.26 kg Optimized SMC
Geometry = 1.34 kg 40% reduction in weight! Steel = 7.31 mm
Optimized SMC Geometry = 19.19 mm Steel = 35.29 mm Optimized SMC
Geometry = 21.17 mm Conclusion: SMC is extremely competitive with
steel. The # of ribs chosen, 35 ensures a FoS of > 2.5 Cost to
Manufacture 38 ribs = $1235 CDN Vertical displacement test Frame
Rigidity Test
Slide 8
Rigid Body Transformation Determine overall door movement based
on Hinge deformation Euler Parameters including Alpha, Beta and
Gamma angles FEA Analysis Right Angle Triangle Points of
Pressure
Slide 9
Rigid Body Transformation Co-ordinates from CAD file
Impact Beam Testing FEA Testing Procedures: Optimization of
wall thickness (3.175mm) ( y x FoS) vs. Mass (@ 1.3kg; 1.6kg;
1.9kg; 2.2kg; 2.5kg) MOI vs. Mass (@ 1.3kg; 1.6kg; 1.9kg; 2.2kg;
2.5kg) Constraints and Assumptions: FoS 3.0 (Reported Industry
Standard) y / FoS > von Maximum allowable displacement: Based
upon 95 th percentile of adult populations sitting hip breadth max
=14.35 cm Impact beam length = 600 mm
Slide 13
Testing Results Optimization of wall thickness: ( y x FoS) vs.
Mass: Impact Beam DesignDisplacement (Magnitude; mm) Stress (Von
Mises; kPa) Factor of Safety (FoS) Square1.823e+0003.819e+0053.1
Square with Rounded Edge2.214e+0004.702e+0052.5 Square with Angled
Edge2.208e+0004.655e+0052.5 I-Beam1.685e+0003.629e+0053.2
Tubular2.332e+0004.564e+0052.6 Statistical Error[(1.0 R 2 )/R 2
]*100% Square0.79% Square Round11.2% I-Beam2.0% Tubular0.64%
Slide 14
Testing Results (cont.) MOI vs. Mass: Impact Beam Selection:
Square and I-Beam (extremely close) Final selection criteria is to
be based upon manufacturability and associated costs Statistical
Error[(1.0 R 2 )/R 2 ]*100% Square1.4% Square Round0.21% I-Beam1.8%
Tubular24.1%
Slide 15
Test & Prototyping Ideas for test plan i.e. Prove viability
of ribs Load String structure with ribs Ends are fixed
Slide 16
Load String structure with ribs
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