1. Workshop :Bicycle Frame Design (Optimization)
University of Puerto Rico at Mayagüez
Department of Mechanical Engineering
Workshop :Bicycle Frame Design (Optimization)
Modified by (2009): Dr. Vijay K. Goyal
Associate Professor, Department of Mechanical Engineering
University of Puerto Rico at Mayagüez
Thanks to Josymir Lopez Ferrer , enrolled in INME 4058
section 2008

2. Problem Description
This is a simple static analysis of a frame of bicycle using a hollow aluminum tube. The schematic dimensions of the bicycle are shown in the figure 1. Initially, the flowing cross-sectional dimensions are used for all frames: Outer diameter φ = 25mm and Thickness t =2mm .
The material properties of aluminum are:
Material Properties
Values
Young’s Modulus (E)
70 Gpa
Poisson’s Ration (ν)
0.33
Density (ρ)
2,580 kg/m3
Ultimate Tensile Strength(σU)
210 Mpa
Elongation at Break
10 %

3. Problem Description (cont.)
Even if the bike is under the dynamic loads, only the static design criteria is considered here: due to vertical bending.
Vertical bending test:
When an adult rides the bike, the nominal load can be estimated by the vertically downward load of 600N at the seat position and a load of 200N at the pedal crank location. When a dynamic environment is simulated using the static analysis, the static loads are often multiplied by a certain “G-factor”. In this design project, use G = 2. Use ball-joint boundary condition for the front dropout (1) and sliding boundary condition for rear dropouts ( 5 and 6 ).

4. Problem Description (cont.)
We want to optimize the bars. For this reason, we are assuming that the following bars will have the same cross-sectional areas:
bars 1 and 4 will have the same cross-sectional area, defined by real constant 1
bars 2 and 3 will have the same cross-sectional area, defined by real constant 2
all other bars will have the same cross-sectional area, defined by real constant 3 .

5. Starting ANSYS From your desktop:
Click on: START > All Programs > ANSYS >
ANSYS Product Launcher.
Here we will set our Working Directory and the Graphics Manager

6. Working Directory Setup
Select the Working
Directory and type
the name of work
shop on Job Name.

7. Graphics Setup Click the button: Customization/Preferences.
On the item of Use custom
memory settings type 128
on Total Workspace (MB):
and type 64 on
Database (MB):
Then click the Run
bottom.
* This setup applies to computers running under 512 MB of RAM

8. Go to customization preferences and choose custom memory settings and give values of 128 and 64 for the total workspace and database memory respectively.
Click Run to start

9. ANSYS GUI Overview
This is ANSYS’s Graphical User Interface window.

10. Step 1: Build the model We have two option:
We can fun the previous tutorial and save the output in VerticalBendingTest.txt
Or, read the VerticalBendingTest.txt (it runs the tutorial directly) .

11. Step 2: Go to Design Optimization
Go to Design Opt> Analysis File>
Create
Assign… File name is: VerticalBendingTest.txt
Now Go to utility menu and read the VerticalBendingTestOptimization.txt file (read input)
Go to Design Opt> Design Set>List (choose ALL sets). This gives you the various iterations .

12. Step 3: Now use this model
From this point on you can use this model to perform all other analysis. .