Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

MSc VIVA

243 views

Published on

  • Login to see the comments

  • Be the first to like this

MSc VIVA

  1. 1. Formula Student Chassis
  2. 2. Formula Student Competition in which universities design, build and run their vehicles with the aim of scoring as many points as possible in the following areas: • Design • Business Plan • Cost • Acceleration • Skid Pan • Sprint • Endurance & Fuel Economy Key PointsWhat is Formula Student • Small engine displacement – 600cc • Very narrow coned track • Emphasis on agility not outright power or speed
  3. 3. • Design a chassis for the 2012 Formula Student Vehicle • Develop an analysis method to help future chassis development Brief Exploration • Performance Increase • Can be confidently manufactured on time • Within budget • Software for chassis analysis • Test of chassis Constraints • Must meet Formula Student regulations • Interface with other major systems; suspension & powertrain • Analysis methods must be usable by future students Timeframe • Final designs to be reviewed in January • Manufactured by 1st May
  4. 4. Research – Chassis Types Steel Tubular Spaceframe Composite Monocoque • Relatively easy manufacture • Cost effective • Previous experience • Inexperienced in manufacture • Relatively expensive • Possible performance gain
  5. 5. Research - Chassis Requirements Considerations Constraints • Track & wheelbase • Ride height • Suspension • Engine & drivetrain • Driver Templates • Cockpit template • Frontal chassis template • Roll hoop requirements • ‘Percy’ – 95th percentile male • Weight distribution • Suspension requirements • Variance in driver size • Load paths
  6. 6. Development Suspension hard points Vehicle Centre Main roll hoop Front roll hoop Steering wheel plane Maximum/minimum driver size Ground plane
  7. 7. Manufacture 8 Week lead time
  8. 8. Purpose • Chassis has a major impact on vehicle performance • No current proven simulation model or test equipment Development Model Options • Finite Element Analysis o Optimisation of chassis in design phase • Physical testing o Requires test rig o Time consuming o Vehicle is already manufactured • Physical test work of a previous chassis • FEA simulation of a previous chassis • Validation of modelling and simulation techniques from test work • Model parameters can be used for future chassis designs Conclusion
  9. 9. Finite Element Analysis Software Package • Solidworks • Abaqus • Other software packages Modelling Methods • Frame constrained to replicate dynamic loading scenarios • Beam element model used o Fewer elements required for a given structure size o Method is readily available and usable in Abaqus o Linear stiffness matrix used Data • Torsional Stiffness o Performance indicator o Comparison to previous frames • High/low stress areas • Comparison of designs o Ultimate stiffness o Mass o Stiffness per unit mass Future use
  10. 10. Testing Method Hub Boss Steel box section 100mm x 100mm x 5mm
  11. 11. Testing Procedure • Aim: Measure torsional stiffness • Dial gauges located between the spaceframe and the flatbed Dial gauges • Front clamped down • Rear set-up on pivot Pivot Rear beam • Masses placed on one side of rear beam (5Kg increments) Masses Front beamPhil’s Shoe • Gauges measured at each interval
  12. 12. Results FEA Results Graph Linear graph – Load applied is directly proportional to angular displacement Test Results Graph Vertical displacement to angular displacement
  13. 13. Results Comparison of Simulated and Tested Data – With Engine Overall Stiffness (Nm/deg) Front to Centre Stiffness (Nm/deg) Centre to Rear Stiffness (Nm/deg) Tested with engine 1462.75335 1880.519508 6602.482826 Simulated with engine 1273.056176 1598.578421 6251.73906 Simulated Percentage Difference -13.0% -15.0% -5.3%
  14. 14. Results Comparison of Simulated and Tested Data - Without Engine Overall Stiffness (Nm/deg) Front to Centre Stiffness (Nm/deg) Centre to Rear Stiffness (Nm/deg) Tested without engine 955.5590512 1568.896077 1768.588146 Simulated without engine 1117.957557 1548.504062 4020.847449 Simulated Percentage Difference + 12.3% -1.3% +127.3%
  15. 15. Results 68 Nm/deg/Kg 72% Increase 34.4 Nm/deg/Kg 39.5 Nm/deg/Kg
  16. 16. Summary • Chassis designed and manufactured on time • All sub-systems fitted correctly • Mass of 29.5Kg - 29% mass saving over previous spaceframe • Vehicle competed at scheduled events Part 1: Design a chassis for the 2012 Formula Student Vehicle • Simple test rig designed and manufactured • Abaqus model of PFK-01 and HARE 12 created • Validation has proved promising • Further validation work required, particularly regarding engine Part 2: Develop an analysis method to help future chassis development
  17. 17. Questions

×