Element H: Prototype Testing and Data Collection Plan

Introduction

In order to know if a solution can work you need to test it. Our main item we need to test is friction. We have three different methods to test friction using several different methods. It is important to use multiple methods to test a criteria to make sure one of the test aren't flawed and to collect as much data as possible. It is also necessary to test the other sub criteria that are needed to your product, for us we need to test the comfort ability and how much static electricity does it generate.

Tests

Friction test one - Varied Weight

1. Place shoes on floor surface

2. Place 200lbs on the top of the shoe

3. Place a scale along the back side of the shoe

4. Apply force on the scale

5. Gradually apply more force until the shoe begins to slip

6. Measure the force that was applied when the shoe began to slip

7. Remove 20lbs from the shoe and repeat steps 1 through 6

8. Repeat step until you get down to 20lbs

9. Record data

10. Graph data with Normal force on the x-axis and friction on the y axis

11. Find the line of best fit

12. The slope of the line of best fit is the coefficient of static friction

Friction test two - COF#1

1. Place shoes on a flat surface near an edge on floor surface

2. Place a pulley on the edge

3. Tie a string to the shoes in a way that the string pulls the center of mass

4. Place the string on the pulley

5. Start adding weight to the other and of the string

6. Add 5 grams until the shoe starts to slip

7. Divide the weight tied on the string by the weight of the shoe to get the COF

Friction test three - COF#2

1. Place the shoes on an incline

2. Increase the incline’s angle until the shoe starts to slip

3. Record the angle

4. Take the tangent of the angle to find the COF

Harness test one

1. Put shoes on test subject

2. Put harness on test subject

3. Safety check

4. weigh test subject

5. lift up test subject from harness

6. reweigh test subject

7. repeat until test subject weighs 1/6th their original weight

8. have test subject try to walk on floor

9. repeat multiple times with multiple subjects

Static test one

1. Rub shoes on the ground 6 inches each in 1 second 30 times to build up a static charge

2. Bring shoe close one inch to electroscope

3. See if electroscope arm moves

4. Measure the angle of deflection

5. Repeat 1-3 15 more times.

Multi-size fit test

1. Place shoes on feet size 9, 10, 11, and 12.

2. Have test subjects walk around and do other basic actions (standing up, sitting down, running, bending over etc.) for 10 minutes

3. Take statements on how comfortable the test subject finds the shoe and how easy it was to walk around in it.

Wear/comfortably test

1. Take an initial analysis of the sole, seams, velcro and fabric condition

2. Have test subject wear shoes all day

3. At the end of the day analyze the sole, the seams, the velcro, and the fabric.

4. Take statements on how comfortable the subject found the shoe.

5. Repeat with different subjects

Fire Resistance Test

1. Take a sample of each of the materials and prepare each to be put into an environment with a controlled temperature.

2. Increase the temperature to 400 degrees Fahrenheit (204.44 C) inside a conventional oven or other controlled heating source.

3. Place the samples into the environment for 3 minutes then remove.

4. Record temperature and observations from the samples.

Durability Test

1. Using the sole of the shoe position the sole above the silicone floor pad parallel to the pad.

2. Proceed to lower the sole of the shoe to the floor pad and pull the show toward yourself.

3. Lift up and reset to the front of the pad and repeat the pulling motion 1000 times.

4. Mark down any wearing that happens to either the floor pad or the sole.

Things to note (After the talk with Mr. Ballentine)

1. During the string tests with our shoe, we must be careful to pull from the center of the mass of the shoe or else the shoe will undergo a rotation and give inaccurate data.

2. When using the spring scales we might have to use multiple scales to be able to measure the full force due to the the limit of the measurable range.

3. When using an electroscope we should use the good version that Mr. Ballentine suggested, and printing out our own angle scale to measure the angle of deflection.

Conclusion

We are testing our design of shoe and seeing how it holds up against the criteria we had set earlier. We are testing things like friction multiple times to get as good of data as possible on it, but we are testing things like fire resistance fewer times as that is less necessary. The scaling of the criteria we set earlier is a guide for our decisions and tests here. We will use these tests to determine if our initial design was good enough, and if it isn't we will use the data to make the proper changes.

Sources

Methods Used for Friction Testing. Texas A&M University College of Engineering. (n.d.). Retrieved December 22, 2021, from https://microtribodynamics.engr.tamu.edu/methods-used-for-friction-testing/

Walpole, S. C., Prieto-Merino, D., Edwards, P., Cleland, J., Stevens, G., & Roberts, I. (2012, June 18). The weight of nations: An estimation of adult human biomass. BMC public health. Retrieved December 16, 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3408371/