Roll Cage Analysis Design Analysis Using Experience and

Roll Cage Analysis Design Analysis Using Experience and Failure to Improve Design

Objectives and ESLR • Review Design Analysis • Review the three scenarios of impact Design Analysis • Compare vehicle structure with added safety (roll cage and 5 point harness • Calculate vehicle mass and necessary safety cage strength • Use buoyancy to find center of mass • Compare impact on human body

Design Analysis Three Impact Scenarios 1. Side Impact 2. Head-on Collision 3. Roll-over Impact Crash Analysis- Pikes Peak http: //www. youtube. com/watch? v=S 6 V 38 e. SUPQM

http: //www. youtube. com/watch? feature=fvwp&v=f. Noqn 7 JQ 250&NR=1 VIDEO- BACKGROUND INFORMATION INSTALL A ROLL CAGE SEE VIDEO QUESTIONS – INSTALL A ROLL CAGE

Side Impact. Student Response Question The human body can withstand 10 times the force of gravity, before passing out. The basic equation is Newton’s First Law ΣF=mxa Vehicle mass = 700 lbs What is the force on a vehicle traveling 30 mph

Side Impact- KEY The human body can withstand 10 times the force of gravity, before passing out. The basic equation is Newton’s First Law ΣF=mxa Vehicle mass = 700 lbs The force equals 7000 lbs.

Side Impact with Triangulation is added to provide driver with greater protection. Stress are highlighted for areas where gussets are to be welded to strengthen the joint. Note: Static analysis causes deformation to magnify Dynamic analysis provides accurate representation but is not available in standard software

Steel Used Chromalloy is stronger and lighter that 1018 steel. Note: Wall thickness of equal strength Chromalloy is thinner and thus lighter Diameter and wall thickness calculations are as follows; M is the moment, σ is stress, I is moment of inertia, C is the distance from the centroid to the point of interest, D is the outer diameter, and d is inner diameter. These equations yielded a necessary O. D. of 1. 25” and wall thickness of. 065”

Testing for resistance to rollover and floating Objective of the SAE Baja design – make it float 1. This was done using the basic principle of density. One simple way to determine whether or not something will float is to compare its density with that of the fluid in which it will be placed in. An object’s density is defined as its mass divided by its volume 2. Two pounds per cubic foot is the highest specific volumes for the closed-cell foams that would be used in this design 3. . Metacentric stability is defined as a vessel’s tendency to produce a moment that will either return the vessel to the upright position or cause it to capsize Lastly was the consideration of notching This team has found a way to effectively notch tubing using a chop saw.

Floatation Design Why is buoyancy used with Baja Design? In order to locate a vessel’s metacenter, shown below, a vertical line is drawn through the center of buoyancy that intersects the vessel’s upright center line. The vessel shown

Does deep diving matter Compare restrictions of a deep sea diver to a driver of a Baja race vehicle Who passes out? Who has the most impact on there body?

Does deep diving matter? See slide 5 for the impact on body of Baja driver