ANSYS AIM HIGH SCHOOL PROJECT GUIDEOFFICE CHAIR DESIGNSCHOOLPeters Township High School (McMurray, Pennsylvania)
INSTRUCTOR
Christopher Allen

CONTACTallenc@pt-sd.org

PROJECT OBJECTIVE
Design an office chair based on predefined parameters
PROJECT OVERVIEWThis project follows the iterative design method (prototyping, testing, analyzing, and refining thedesign) to achieve minimum requirements with a primary goal of a project-based approach tostructural design. It is completed in a digital format using ANSYS AIM to test designs, but canbe adapted to include a traditional manufacturing component. Minimum project requirements
are taken from the Americans With Disabilities Act (ADA) and modern manufacturing standards.
PROJECT STRATEGYThis project relies upon the scaffolding method in education culminating with a project-based
challenge. Prior knowledge includes parametric modeling techniques, structural engineering
concepts, product development concepts, product design techniques, manufacturing standards,and material science. As the final project for the course, students are presented with this projectin three overall phases: research, design and testing, and final presentation.
Research Phase:​ As an introduction to this project, students begin with a experiential research
assignment that requires they develop and utilize an evaluation system for current chairs on themarket. Then they meet and interview other people who work in office environments tounderstand what they expect and would like in a new type of office chair.
Design and Testing Phase:​ Students begin preliminary designs in the form of rough sketches
and moving on to technical drawings. This leads them into the parametric modeling phase of
the project and then into structural analysis of their designs using ANSYS AIM. Finally, students
evaluate the data from the structural analysis and use it to iterate on their design. With eachnew iteration, at least five required, of their design they test the structural performance underthe given loads to reach a final design.
Final Presentation Phase: ​This phase requires a presentation which outlines their process ineach of the three overall phases, as well as a visual demonstration of their iterative designprocess.

EARTHQUAKE RESISTANT BUILDINGREQUIREMENTS AND GRADING RUBRICDIRECTIONSDesign a new type of office desk chair based on the ​Design Requirements​ ​and ​Dimensional
Requirements​ ​listed below. The structural integrity of the chair will be tested using ANSYS AIM
simulation software. The parameters of the simulation and how you will be graded is listedbelow.
DESIGN REQUIREMENTS
Seat
Legs: 3-5 individual

Backrest

Armrests

Legs: Only part touching ground

Aesthetic Design: ​Aesthetics is a study of the mind and how our brains interpret something
as being beautiful or ugly. It is crucial for design because our first interaction with almost
anything is based on how it looks.
Ergonomic Design:​ Ergonomics is the science of refining the design of products to optimize
them for human use. Human characteristics, such as height, weight, and proportions areconsidered, as well as information about human hearing, sight, temperature preferences, andso on. Ergonomics is sometimes known as human factors engineering.

*Use the above diagram as a reference for the ​Dimensional Requirements ​on the next page.

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DIMENSIONAL REQUIREMENTS
Max Material Thickness

3”

Range of Overall Width of Seat (Not Overall Chair Dimensions)13.9” – 18.0”

Range of Backrest from Seat Height (A)31.3” - 38.3”Range of Waist Depth (C)7.3” – 11.4”

Range of Thigh Clearance (D)21.0” – 26.8”

Range of Back-to-Knee (E)21.3 – 26.3”

Range of Seat Depth (G)16.9” – 21.1”

Knee Height (F)19.8” – 28.0”

Range of Seat Height from Ground (H)19.8” - 25.0”

Distance Between Armrests

16.5” − 19.0”

Max Height80”

Max Width32”

GRADING RUBRICStructural Efficiency (10 pts.)
Mass of Chair
Weight Requirements: ​Test the structural integrity of your chair design using the following weights,
converting them to​ Pascals​ first.
1 pound = 6894.76 Pascals
Pounds275

300450 (Bonus)

Newtons
Structural Efficiency Score: ​Use the structural efficiency equation to determine your structural
efficiency score. In the box below calculate your structural efficiency score based on your results andshow your work. The Mass Held amount should be the weight held by your chair with ​no yellow areas
during the ​Equivalent Stress simulation.
Mass Held / Mass of Chair = Structural Efficiency Score

3Simulation Results (60 pts.)
Equivalent Stress (40 pts.):​ If the maximum value of equivalent stress induced in the material ismore than strength of the material the design will fail. Points are awarded based on the performanceof your design in the simulation.
Weight275

300450 (Bonus)

StressBelowYellow

Yellow

BelowYellow

Yellow

Below Yellow

Value

30

20-29

40

31-39

50

Displacement Magnitude (20 pts.): ​Distance, as measured directly between the start point and theend point with no directional consideration.
Below Yellow

Yellow(based on the number of contact points)

Above Yellow

56-19

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Design Evaluation
Design Requirements Adherence:​ Minus 10 pts. from final grade for every missing partSeatBackrest

Legs: 3-5 individualArmrest

Legs: Only part touching ground

Dimensional Requirements: ​Minus 5 pts. From final grade for every infraction
Aesthetic Design:​ Minus up to 5 pts. from final grade based on quality of aesthetic
Ergonomics:​ Minus up to 5 pts. from final grade based on quality ergonomic design

4EARTHQUAKE RESISTANT BUILDINGSIMULATION PROCESS GUIDE
1. ANSYS AIM and File Setup
a. When AIM opens you will see the following screenb. In the ​Study​ ​Panel​ select ​ ​Structural​ ​for the Simulation Process Template5

c. On the next menu, ​Structural Template, ​everything for the project file should beset and look like the following image.

d. Click ​Create Simulation Process​ and a panel will open to ​Import Existing
Geometry, ​which is where you will​ ​select your ​ STEP File (.STP)
2. Prepare and Edit Geometrya. Once your geometry has imported you will be looking at a new window with 3
important areas we will be using to set up our simulation

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i.

Area 1 - Geometry View

ii.

Area 2 - Workflow

iii.

Area 3 - Simulation Process7

b. Next we need to use the built-in CAD software to combine all of our individual
parts. In the ​Simulation Process 1 ​ ​panel​ click on the word ​Geometry​.

c. In the next panel you can either ​Replace Geometry​ or ​Edit Geometry

3. Preparing the Mesha. In the ​Workflow ​area select ​Mesh​.

b. In the ​Simulation Process panel​ do not make any changes and click ​Generate
Mesh​.

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c. The chair will now look like it has a net all over it which is the ​Mesh. ​The meshrepresents the discretization of the physical domain into a mathematical model.
The mesh enables AIM to assemble a system of equations, which are used tocompute the physical response of the domain.

4. Assign Physics to the simulationa. In the ​Workflow ​ menu select ​Physics

b. In the ​Physics Process panel​ find the ​Structural Conditions ​item. Click on theAdd​ button and select ​Support​.

c. The ​Support 1 panel​ will open in the top left of the screen and under theLocation ​box we will need to add the area of our model where the support of theground will be located. In our case it will be at the bottom of each leg​.

9d. Next, navigate to the ​bottom​ of your ​chair​ by ​clicking on the chair anddragging your mouse until you can see the bottom.

e. To actually select the bottom of the legs you need to use the ​Selection Buttons
located in menu on the​ top-right​ of the screen. Make sure that the F​ ace
Selection​ button is selected which is indicated by the it being shown as orange.

f.

Click the ​Bottom Face​ of each leg ​holding CTRL​ ​to select this face, which willturn orange.

g.

​Finally, with the face selected go ​Support 1​ ​Panel​ and in the ​Location ​box clickthe ​Plus Button​ ​to add the face to the ​Support 1 Condition​.

5. Define the Pressure Structural Condition
a. Return to the ​Physics Process Panel​ by selecting it in the ​Workflow Panel​.
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b. Add another ​Structural Condition ​using the ​Add​ button located next to theStructural Conditions​ line and select ​ Pressure​.

c. The ​Pressure 1 ​ ​Conditions​ ​Panel​ will appear in the top-left of the screen andjust like with the ​Support 1​ condition we will need to add a location where thepressure will be applied to our structure.
d. Using the same method of navigating around the chair, select the ​top face​ ​ofseat.

e. Add these to the ​Pressure Condition​ by clicking the ​Plus Button​ in thelocation ​line of the ​Pressure 1 Panel​.

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f.

Next we need to define the amount of pressure to be applied to the locations thatyou selected. Enter the amount of ​each weight of the test requirements inPascals.

g. Finally, click the ​Physics​ button located in the ​Workflow​ menu to return to thePhysics Process Panel​. To complete the Physics portion of this simulation clickthe ​Solve Physics​ button located at the bottom of the this panel.

6. Run the Simulation and Evaluate Resultsa. Click Evaluate in Workflow

b. In the ​Evaluate Process Panel​ click on the ​Evaluate Results​ button to run thesimulation.

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c. The ​Results Process Panel​ will have then show an ​“Up to Date”​ symbol ingreen.

d. Now we can see the results by click on the word ​Results​ in this panel. Doing thiswill bring up another menu with two items, ​Equivalent Stress​ and ​Displacement
Magnitude. ​ ​Clicking the arrows located in the top-left​ will allow you tonavigate between the two results.

e. Selecting one of these will bring up the results with the option to play ananimation of the simulation. To play the animation click on the play button locatedabove your building.

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7. Document Resultsa. Navigate the camera to a view that shows your entire design.
b. Right-Click ​on your design and then click ​“Save Image As…”

c. In the ​“Save Image As” ​box that opens click on the button to the right of the“File” ​box that has ​3 dots​ and select your H​ : Drive​ to save each picture14