INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • 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.

Jobs

Impact loading on driveline

Impact loading on driveline

(OP)
Hi,

I work in a company that design driveline components for on-road truck, from light duty f450 to full size city buses.

I’m routinely doing stress analysis on different component (flange, splined connection, shaft..) that are located somewhere in the driveline between the differential and the engine. Unfortunately, we aren’t integrator so we don’t have that much information about real life load cases for these component.

I’m curious about the dynamics/inertia loading in the driveline caused by impact, pothole, wheel slippage on ice… The worst I can imagine is wheel spinning on ice then catching on the asphalt. I wondering if this kind of event lead to significant torque loading in the driveline. Does the driveline components between the road and the engine have enough compliance to filter the shock. We usually suppose an amplification factor on the maximum engine torque to do the stress analysis. What kind of amplification factor is realistic?

Machinery’s handbook specify some amplification factor varying from 1 to 2.8 for involute spline calculation depending on power source and load type.

Does anybody have some experience on that subject?

Thanks

RE: Impact loading on driveline

"The worst I can imagine is wheel spinning on ice then catching on the asphalt."

In that instance a significant portion of the torque generated by hitting the asphalt, is dissipated in slowing the spinning wheels, so the shock loading is not as bad as you think.

Far worse is the clutch-dump launch on asphalt, where the torque required to accelerate the wheels is added to the torque required to break traction.

je suis charlie

RE: Impact loading on driveline

(OP)
You are right. The clutch-dump situation is probably harder on the drive line that the wheel spinning on ice.

In both situation, I think the main source for the shock loading is the high inertia of the diesel engine. In both cases, there is a rapid engine deceleration that leads to high torque on the driveline. This load case is severe because the driveline see the max engine torque (if the throttle is wod) + the inertia torque. I tend to think that driveline compliance has a great influence on the inertia torque. A more rigid driveline leads to quicker deceleration and higher inertia torque.

I don't have any kind of real life value for these situation. I'm looking for these number.

RE: Impact loading on driveline

The proper way of doing it is this, or equivalent

http://www.kasensors.com/en/products/drive-shaft-t...

If you can't instrument a vehicle then one option would be to build a dynamic system model of the driveline and then use an accurate RPM trace from the engine, and ideally the output from the ABS tone wheels, and then stuff around until you get a good match. The rate of change of rpm tells you a great deal.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

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.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources


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:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close