×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# Braking force calculation2

## Braking force calculation

(OP)
How do I convert an engineering callout of "must having braking force of 0.6g with pedal force of no more than 80 lbs" into a measurable force (ideally in newtons) that I can use to measure on a chassis dynameter (aka rolling road) in a production environment? We normally just check braking force go/no go; however, we are looking to check a brake bias between front and back and want to get a more meaningful number from the engineering callout.

I have the vehicle weight + CG, rolling road roller diameter, and am working on getting the coefficient of friction for both the tire and rolling road roller surface.

### RE: Braking force calculation

Knowing such things as brake pedal ratio, master and wheel cylinder diameters, mean radii of the various disc swept areas, and wheel rolling radii would probably help.

Actually, it's not a bad little problem to throw into a spreadsheet.

Norm

### RE: Braking force calculation

F = M*A

.6 g of acceleration will result from a force equivalent to 60% of the vehicle's mass.

### RE: Braking force calculation

(OP)
Thanks! jgKRI - I'm concerned that the callout is for stopping the vehicle in road conditions, while the test will be conducted when the vehicle is static. In that case I think what I'm looking for is the force that can be generated by each wheel on rollers - I think I can pull all those variables and go from there. We can take a few known good units (that pass the 0.6g test in field conditions) and back in to a required force that the brakes have to generate.

### RE: Braking force calculation

You know that to meet .6 G of acceleration, the forces at each contact patch must, at minimum, sum to 60% of vehicle mass. The mass of your dyno rollers is a known, so by recording the amount of time it takes for the car's braking system to stop the rollers from a known speed, you can determine very easily if the braking system is capable of your requirement. Unless you need to know the actual forces on the individual parts, you don't need to do a deep dive into the hydraulics.

The only major variable that the dyno test won't account for is weight transfer- when you apply the brakes on the dyno, you will get no (or at least much less than in real-world conditions) weight transfer between the front and rear axles.

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

#### Resources

Research Report - How Engineers are Using Remote Access
Remote access enables engineers to work from anywhere provided they have an internet connection. We surveyed our audience of engineers, designers and product managers to learn how they use remote access within their organizations. We wanted to know which industries have adopted remote access, which software they are using, and what features matter most. Download Now
eBook - Managing the Context of Product Complexity Using the Digital Twin
Keeping track of changes to complex products is difficultâ€”think Aerospace & Defense equipment, new generations of commercial aircraft, and software-based automobiles. A new way to managing the digital context of the physical product is required and the answer is the Digital Twin. This ebook explores the opportunity available for Operations and Maintenance for the Digital Twin. Download Now
White Paper - Trends in Industrial Filtration
Substantial progress has been made in filtration technologies in recent years. New filter media materials, designs and processes have led to filters that are more efficient, reliable, compact and longer lasting. This white paper will discuss the various trends that are impacting operational responsibilities of MROs today and the resources that are available for staying up-to-date on the latest filtration solutions. Download Now

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!