Driveshaft Loading and unloading Finding Stresses 1

[Chevykid18]

I need to design a driveshaft, that when in first gear needs to transmit 500ft-lbf. My ideal shaft would be light weight as I am trying to cut down as much as I can on rotational interia and mass. What I did was a static FEM analysis clamping one end with 0 degrees of freedom and applying the torque to the other end of the shaft. With a solid one inch shaft, I was getting about 10k less than yield stress. I don't trust these values. For example, On a GEO metro, They put 600ft-lbs to the driveshafts and the shaft itself is only appx 7/8"dia. Any help/guidance in this area of torque transmission and also impact loading on the shafts is needed. thanks

 

[GregLocock]

What yield stress are you using? Are you aware that halfshafts are made of very good steel?

Bear in mind that even production cars run into problems with yielding halfshafts.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Chevykid18]

We were planning on using on 4130 steel hollow shafts, and from matweb.com we said the yield stress was 61kpsi.

thanks,
Pete

 

[sreid]

You are looking at 4130 in the normalized condition. For a hardened tube the yield is likely to be above 150 ksi.