Overview of Status of Analysis, Design, Fabrication, Tests, etc.
Analytically modeled collision as a 2-DOF mass-spring-damper system
Numerically modeled dynamics of “swinging hammer”
Bearing research
Pricing on foams, metals
Accomplishments from Previous Week
Started working on individual component analysis
Foam/plate costs - Sam, Leighy
Unconstrained 2 DOF system modeling - Roy
Hammer bearing force analysis (bearing force changes throughout swing) - Troy
Goals for Next Week (list names after each item). Use specific and measurable objectives.
Determine which further foam characteristics are to be calculated using previously collected data - Leighy
Start figuring out general bulk/dimensions of hammer supporting frame - Leighy
Review calculations to ensure accuracy before physical testing - all (primarily Roy/Troy)
Find initial velocities/structural stiffnesses to achieve given impulses
Convert Vinitial to some spring deflection (impact head will likely be hammer + spring assist)
No spring will be too slow for any profile, full spring compression will be too fast for any profile
Note: above scheme means hammer has wider range of adjustability than needed; THAT IS A GOOD THING
Finalize drop scheme (side impact? overhead?) - ALL
Heavily influences arresting method
Finalize fixture plate and foam base sizes, (impact orientation influences this) - All (primarily Sam)
Possibly begin preliminary optimization: minimize weight for high natural frequency (pocketing of material) - Sam
Sponsor Comments from Last Meeting and Actions Taken to Address these Comments
Ruled out possibility of using swinger/slider for reasons of rigid body rotation/introducing undesirable vibrations
Also excessive cost and increase in scope
Gave us 3 samples of foam to determine properties for the foam base; group did compressive load testing and figured out the names of the 3 types of foam and their properties
Came to the agreement that using a foam base was best option
Instructor Comments from Last Meeting and Actions Taken to Address these Comments
Convert all units to S.I. units, which we have done now for all calculations/formal reports
Results somewhat inconclusive from risk reduction—still need to determine what we are comparing the natural frequencies of the foam to
Will have further discussions with ATA: they are good at science
Risks and Areas of Concern
Limited costs - foam base + metal fixture plate will likely take up entire budget (unless ATA or a dumpster has some materials for less)
Still have an impact head (hammer) AND its (likely massive) supporting structure to cost
Resources or Information Required but not Available
None at the moment, ATA will provide information/resources that we ask for
Schedule
Finish individual component research draft - 04/02
Finalize by 04/03 (duh)
Finalize impact scheme - 04/03
Finalize plate/foam dimensions - 04/04
Find initial velocities/structural stiffnesses to produce desired half sine impulses (basically should be a table: 3 scenarios, w/ one velocity and one structural stiffness each) - 04/05
Convert Vinitial to some spring deflection - (hopefully 04/06, but can be pushed back until after ATA meeting)
Budget (list amount spent and amount remaining)
$1500 remaining, we began calculating how much all of the components will cost/where to get them
Progress on Report and Webpage
Individual analysis reports going well and each will be uploaded to webpage
Webpage shall be maintained better beginning Thursday after Sam is done doing racecar documentation; start on the following:
Student Bios (pictures would be nice)
Project description (pictures would be nice)
Other presentations to ATA
Cool pictures (pictures would be nice)
Cool animated things (animated things would be nice)
Bad website design practices from the 90's