ME 2019 Senior Design Team 512

Vehicle Performance

This section highlights T-Bone's performance characteristics including individual's top speeds, FEA analysis, and performance data.

Vehicle Video

Performance Data

Top Load
The frame was tested in PTC Creo appling a 2670 Newton force at 12 degrees from vertical. Testing revealed that a max von Mises stress of approximately 391 Megapascals was observed.

✅APPLIED TOP LOAD WILL PASS STRUCTURAL TEST

Side Load
The frame was tested in PTC Creo appling a 1330 Newton force at shoulder height on the frame. Testing revealed that a max von Mises stress of approximately 133 Megapascals was observed.

✅APPLIED SIDE LOAD WILL PASS STRUCTURAL TEST

Performance Requirements

To be able to enter the ASME HPVC 2019, certain vehicle peformance parameters needed to be met. These include:

• Vehicle must be able to brake in 6-meters from a velocity of 25 km/hr.

• Vehicle must be able to complete an 8-meter radius turn.

• Vehicle must possess a Roll Protection System (RPS).

Braking Test

Turning Radius Test

Competition at the College of Engineering

Having met our objective of creating a vehicle capable of entering and competing in the ASME HPVC 2019, Team 512 elected to emulate the events of competition at the FSU-FAMU College of Engineering.

• Team 512 chose to recreate the ENDURANCE event in the COE's parking lot. The track stretches 1-kilometer and replicates the obstacle course present at competition. The ENDURANCE event consists of speed bumps, stop signs, hairpin turns, a slalom, a rumble strip, and a quick turn.

• Team 512 chose to recreate the SPEED event on a 270-meter straight and level stretch of road close to the COE.

Number	Obstacle
1.	Speed Bump
2.	Stop Sign
3.	Hairpin Turn
4.	Slalom
5.	Rumble Strip (potholes)
6.	Quick Turn

Vehicle Specs

Description	Unit
Material	Low Carbon Steel
Length	2.13 m
Width	1.08 m
Height	1.29 m
Wheelbase	1.07 m
Weight Distribution (Front)	18.1 kg
Weight Distribution (Rear)	13.6 kg
Total Weight	31.7 kg
Wheel Size (Front)	0.508 m
Wheel Size (Rear)	0.660 m
Frontal area	0.81 m²
Steering	Front
Braking	Front
Estimated Coefficient of Drag	0.8
Maximum Competition Velocity	27.36 km/hr

Future Work

Testing and analysis completed, Team 512 assessed what improvements could have been made on T-Bone and for what reason. Addressing this information is detrimental to the understanding that as engineers, something more can always be done. This section highlights and proves these suggestions for future seniors of the FSU-FAMU COE that inherit this project.

Energy Study

This figure displays the power required to accelerate T-Bone to maximum competition velocity. Changing the material of the frame, a trend can be observed that lighter materials require less power to accelerate.

This figure displays this same power vs. time information, but over a scale of greatly increased velocity. This was to demonstrate the effectiveness of fairing usage; a feature that is better observed at high velocities where larger air-drag forces are factors. Fairing eliminated an observable amount of power to accelerate the vehicle at these increased speeds.

This figure displays and compares the Newton Forces different framework materials (Steel, Aluminum, Carbon Fiber) experience at certain velocities. An important trend to observe is the velocity at which the forces due to DRAG surpass the forces experienced by friction. When a lighter material is used, a lower frictional force is present that the vehicle must overcome.

Power Study

The top speed recorded with T-Bone was 7.6 m/s (17 mph). During the power study, the velocities at which drag forces overpass forces experienced by friction and inertia are observed. Being the lightest material, drag forces become dominant for the Carbon Fiber frame at just 11 m/s.

Current Steel Frame:

• Drag force overcomes inertia at 7 m/s (15.6 mph)

• Drag force overcomes friction at 24 m/s (53.7 mph)

Aluminum Frame:

• Drag is the significant force at 15 m/s (33.5 mph)

Carbon Fiber Frame:

• Drag is the significant force at 11 m/s (24.6 mph)

Conclusions

Team 512 suggests a reconstruction of frame to a lighter material such as aluminum or carbon fiber to decrease the required power to operate. After the mass of the frame has been lowered, aerodynamic devices can then be added.

Estimated Raw Material Cost:

Aluminum Tubing: $70

Carbon Fiber Tubing: $1200 - $1800

Carbon Fiber Fairing: $1000 - $2000

When the mass of the vehicle has been reduced to 40 pounds, it is no longer financially beneficial to further decrease the weight. Aerodynamics should be considered.

The use of a CFD analysis to calculate the drag coefficient of the vehicle and air flow patterns is highly recommended. The frontal area calculation through a CFD analysis is also recommended. This will offer more accuracy if another dynamic energy equation would be analyzed for the vehicle.

Future teams may also find benefit from researching customized gear sets in order to improve mechanical advantage provided by the system. The current design of the drivetrain does not allow the vehicle to be low to the ground, thus making the frontal area larger. If this can be changed in a future iteration, then the aerodynamics and drivetrain would be improved.

The use of a universal joint to transfer rider input force to the driving wheel could be an option for this case. The frame uses two steel members going down the length of the vehicle and could be subject to high torsion forces bending the frame out of place. Redesigning this feature to be a singular steel tube with a larger radius can remove this possibility. An additional improvement would be to adjust the positioning for the handlebars.