Fig 1. Interface of windows app used for motor and esc qualification with customizable values

Fig 2. Ramp profile to be used for motor and esc qualification test

Fig 1. CAD design of fixtures for testing in static and fatigue conditions

Fig 2. Manufactured fixtures for testing using CNC machining, waterjet, lathe

Fig 3. Laser scanning using FARO arm of metal leaf spring to determine geometry

Fig 4. Manufactured mold in 5-axis CNC using laser scanned geometry for composite layup

Fig 5. Trimming of cured composite leaf to required dimensions using wooden trim tool on 5-axis CNC

Fig 6. Layup of stepped flat leaf with silicon dams around to prevent resin flow

Fig 7. Manufactured and assembled hybrid composite leaf spring

Fig 8. Testing apparatus for static and fatigue load cases

Fig 9. Extreme deflection of composite leaf spring to check strength

Fig 10. Experimental location of strain gauges (red) to composite leaf spring

Fig 11. Small scale flexure testing as function of aspect ratio to speed up testing

Fig 12. Static flexure failure locations for unidirectional samples with aspect ratio 10

Fig 13. Stiffness as function of fatigue cycles for unidirectional samples with aspect ratio 10

Fig 14. Flexure fatigue locations for unidirectional samples with aspect ratio 10 indicating shear failure from stress concentration

Fig 15. Static flexure failure of samples for unidirectional samples with aspect ratio 30

Fig 16. Stiffness vs fatigue cycles for unidirectional samples with aspect ratio 30 - Almost constant, no catastrophic failure

Fig 1. Prepared coupons for tensile testing

Fig 2. Tested specimens to determine strength along different directions

Fig 3. Prepared Mode I fracture toughness samples

Fig 4. Propagation of cracks while testing Mode I fracture toughness

Fig 5. Experimental force-displacement data indicating propagation of crack at load drop

Fig 6. Specimen failing in bending rather than crack propagation due to high bending strength

Fig 7. Fixture for performing IITRI compression test

Fig 8. Strain gauged samples for compression test for measuring compressive modulus

Fig 9. Shear failure in compression test specimens

Fig 10. Experimental setup for calculating Mode II fracture toughness

Fig 11. Crack propagation for different samples in Mode II fracture mechanism

Fig 12. Shear failure of specimens to calculate shear modulus

Fig 13. CAD geometry for stamped control arm to be made using compression molding

Fig 14. Process of formation of tow and fabric

Fig 15. Assignment of principal directions for composite laminate simulation

Fig 16. Displacement contours for bending and compression load cases of composite laminate

Fig 17. Modification of surfaces to reduce stress and displacement results

Fig 18. Geometric modification I

Fig 19. Geometric modification II

Fig 1. Image of Boeing 787 Dreamliner part geometry used for analysis and compression molding

Fig 2. Tsai-Wu value of a layer

Fig 3. The displacement along y-axis of each layup.

Fig 4. Plot of DSC data for resin system

Fig 5. CAD geometry for cutting prepreg : (Left) Optimal placement of +45o laminae on 11.75 inch wide prepreg roll. (Top Right) 90o laminae slits and peg holes. (Bottom Right) 0o laminae slits and peg holes.

Fig 6. Mold assembly: 3-part female half and 1-part male half.

Fig 7. Flash consisting of resin and fiber being squeezed into mold gaps.

Fig 8. Hole in laid up charge with z-directional peg for insertion.

Fig 9. Compression molded final part

Fig 10. Photos of final part with (a) pin and testing arm and (b)mounted on testing fixture.

Fig 11. Photos of Part 1 failure (a) while under load and (b) in a close view after removal from the fixture.

Fig 12. Photos of Part 2 failure.

Fig 13. Photos of Part 3 failure.

Fig 14. Load-displacement curves showing maximum load for each part.

Fig 15. Micrograph showing z reinforcement location before and after molding (highlighted in red).

Fig 16. Micrograph showing delaminations and cracks (highlighted in yellow).

Fig 17. The TEAM

Fig 1. Differential Scanning Calorimetry (DSC) for determining the cure cycle of the polymer

Fig 2. Experimental data from DSC to determine cure cycle for different temperatures

Fig 3. Thermocouples placed on bottom, mid and top of laminate to analyze the temperature distribution

Fig 4. Experimental data obtained from thermocouples for different location of thermocouples

Fig 5. Placement of polymer in DSC to determine degree of cure as a function of temperature

Fig 6. Experimental data for degree of cure as a function of temperature and time

Fig 7. Rheometer to calulate viscosity as a function of temperature, time and shear rate

Fig 8. Experimental data for viscosity as a function of time for different temperatures

Fig 9. Experimental setup for calculating directional permeability from Darcy flow equations

Fig 10. Experimental results for flow fronts to calculate directional in-plane permeabilities

Fig 11. NACA duct layup for curing in autoclave and oven

Fig 12. Final parts after curing in oven and autoclave. Extra resin flow for autoclave part indicates better compaction and less voids

Fig 13. Manufacturing of NACA duct using VARTM process

Fig 14. Final cured part from VARTM manufacturing process

Fig 15. Microscopy of autoclave cured part indicating better compaction and no voids

Fig 16. Microscopy of VARTM cured part indicating higher void concentration due to low compaction pressure

Fig 17. Possible responses of laminated composite ring after curing due to presence of thermal residual stresses

Fig 18. Composite ring layup on aluminum and steel tool to analyze cured residual stresses

Fig 19. Measured experimental displacements after cutting the composite ring due to thermal residual stresses

Fig 20. Compression molding tool for a pin bracket

Fig 21. Compression molded part from PPMC material

Fig 22. Microscopy image showing the flow of fibers in molding and knit line

Fig 23. 3D printed and machined tool for compression molding

Fig 24. Laser scanning of tool surface after compression molding to check for deformations

Fig 25. Deviation of the part from its initial geometry due to compression molding

Fig 1. Effect of symmetric and unsymmetric layup on cured composite laminate

Fig 2. Microscopy of laminate to find fiber diameter, fiber volume fraction and fiber layup angles

Fig 3. MTS machine for tensile loading

Fig 4. Prepared and tested samples for orientation 90, Strain calculated using DIC and strain gauge

Fig 5. Analyzed stress-strain curve for transverse loading from load data by MTS and strain by DIC

Fig 6. Prepared samples for measuring shear modulus with strain gauges

Fig 7. Shear stress vs shear strain plot for data collected

Fig 8. Samples for off axis tensile testing to characterize strength as function of fiber orientation

Fig 9. Experimental strength and predicted strength as function of fiber orientation for different theories

Fig 10. Correlation of experimentally measured displacements from DIC with theoretical results

Fig 11. Flexure testing of samples as function of aspect ratio

Fig 12. Failure mode for longitudinal and transverse samples in flexure

Fig 13. Stress vs strain curve for samples with different aspect ratio in flexure

Fig 14. Experimental setup for measuring the coefficient of thermal expansion

Fig 15. Thermal strains along fiber directions measured from DIC

Fig 16. Thermal strains as a function of temperature

Fig 17. Prepared samples for open hole tension for different hole sizes

Fig 18. Failed specimens for open hole tension for different laminates

Fig 19. Corellation of experimental and theoretical results of failure strength for open hole tension test

Fig 20. Mode I fracture toughness experimental setup

Fig 21. Experimental data for propagation of crack with the increase in tensile force to calculate Mode I fracture toughness

Fig 22. Mode II fracture toughness experimental setup

Fig 23. Experimental data for propagation of crack with the increase in tensile force to calculate Mode II fracture toughness

Fig 24. Compression testing experimetnal setup

Fig 25. Microscopy of failed samples in compression

Fig 26. Failure mechanism for compression testing for different orientations of composite laminates

Fig 1. Original geometry of the cast iron pulley and belt assembly

Fig 2. Simplified geometry for large and small pulley for simulations

Fig 3. Stress distribution in cast iron pulley for given loading conditions showing probable failure locations

Fig 4. Modified geometry for stress distribution and stress concentrations due to 6 radial ribs

Fig 5. Modified geometry for stress distribution and stress concentrations due to 12 radial ribs

Fig 6. Modified design 1 for injection molding

Fig 7. Modified design 2 for injection molding

Fig 8. Modified design 3 for injection molding

Fig 9. Modified design 4 for injection molding

Fig 10. Stress distribution for final injection molded design iteration 4 showing probable failure locations for large pulley

Fig 11. Stress distribution for final design iteration 4 showing probable failure locations for small pulley

Fig 12. Injection molding simulation design and workflow

Fig 13. Warpage in the large pulley as a result of injection molding

Fig 14. Location of air gaps and weld lines from injection molding simulations

Fig 15. Distribution of fiber orientations in X, Y and Z directions

Fig 16. Mapping of fiber orientations from injection molding using Digimat to Abaqus file for structural simulation

Fig 17. Mapped orientations to abaqus file for large and small pulley from injection molding simulations

Fig 18. Stresses from anisotropic structural simulation accounting for fiber orientation from injection molding which leads to overall 14% increase in overall stresses from isotropic simulations

Fig 19. Principal strains from structural simulation accounting for fiber orientations from injection molding

Fig 1. Designed and manufactured formula student car by the team

Video 1. Electro-pneumatic shifting

Video 2. Electro-pneumatic shifting

Fig 1. Experimental setup on 2-ton NC controlled FSW machine

Fig 2. Geometric model of workpiece and boundary conditions

Fig 3. Numerical results for temperature distribution for 1200 rpm

Fig 4. Shoulder and Pin bottom heat flux distribution

Fig 5. Velocity distribution perpendicular to welding direction

Fig 6. Strain rate distribution for various rotational speed at 60 mm/min (a) 900 rpm (b) 1200 rpm (c) 1500 rpm

Fig 1. Complete experimental setup including 4-stroke engine, air supply, air filter and regulator, microcontroller, motor and optical encoder

Fig 2. Model engine operated by air pressue with attached encoder to measure rotational rpm

Fig 1. Tool to manufacture rails attached to the saddle

Fig 2. Tool to manufacture bicycle saddle seating surface using composite layup