Modeling of the Broaching
Process
By:
Sara Whitby
Matthew Glisson
Anton Galkin
Problem Statement
• Linear broaching is material
removal using a toothed tool
• Tool is pushed through
material in a line
• High force
• Very fast
Complications:
• Expensive
• Difficult to design
• No interchangeable parts
Motivation
• Automate computationally
intense parts of design
process
• Allow for rapid iteration
through different design
options
• Explore applications of
course materials
Approach: Matlab Model of Slot Broach
User Input:
• sketch of final profile
• parameters: cutting speed, number of teeth, workpiece
length, basic tool geometry, etc.
Pre-Processing
• determine intermediate profiles
• calculate discrete chip areas
Force Calculation
• numerically calculate and sum forces
Output
• graph results
Program Procedure: Input to GUI
Program Procedure: Outer Profile
• Takes a .png image
• 255 x 250 pixels
• (x,y)=(0,0) at bottom center
• start and end of line must
touch bottom of image
• each black pixel can only
have two neighbors
• outer profile cannot double
over line radiating from (0,0)
Program Procedure: Generate Profiles
• Use MATLAB's polyfit
function to fit curves to x
and y vectors
• Find specified number
curves evenly spaced from
start profile
• Re-relate new x and y
• plot all profiles
Program Procedure: Find Output Data
• Finds small areas between
teeth along each profile
Graphical Outputs:
• All tooth profile shapes
• Plugs incremental chip
thicknesses and widths
into oblique cutting
function
• Outputs forces, velocities,
angles, and geometries for
each tooth
• Total forces over time
• Minimum and maximum
tooth force profiles
• Force profile for user
selected tooth
Graphical Output Example
Graphical Output Example (continued)
Project Outcome
• A program which can simulate a slot broaching process in a
wide range of situations
o Creates evenly spaced tooth profiles from digital images
o Calculates the lateral, thrust and cutting forces over the
perimeter of a specific tooth
o Finds the total lateral, thrust and cutting forces over time
o Automatically displays the highest and lowest lateral,
thrust and cutting forces over the perimeter the first and
last teeth (min and max total forces, respectively)
• The tool can be used when designing a broach to quickly
and easily experiment with different tooth profiles and forces
Future Improvements
• Find intermediate profiles based on total chip areas
• Model force of gradual entry into workpiece by oblique tooth
• Allow for more flexibility in inputs and outputs
• Model different kinds of broaching
• More versatile starting profiles
• Fix distribution of points for outer profile
Questions?
References:
Vijayaraghavan, L., R. Krishnamurthy, and H.
Chandrasekaran. "Evaluation of Stress and
Displacement of Tool and Workpiece on Broaching"
(1981)
Ozturk, Ozkan, and Erhan Budak. "Modeling of
Broaching Process for Improved Tool Design"
Shi, D., D. A. Axinte, and N. N. Gindy.
"Development of an Online Machining Process
Monitoring System: a Case Study of the Broaching
Process" (2007)
Kokturk, U., and E. Budak. "Optimization of
Broaching Tool Design" (2011)
Ozlu, E., S. Engin, C. Cook, T. El-Wardany, and E.
Budak. "Simulation of Broaching Operations for
Tool Design Optimization"