1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Smallest cross-sectional area of rod-end?

  1. Mar 2, 2008 #1
    i was doing some reading on structural mechanics and i stumbled across this example:


    i don't really get the highlighted part. anyone care to explain?


  2. jcsd
  3. Mar 2, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    The pin at C exerts a force of 50kN on rod BC. In the middle of the rod, the cross section is circular, and we calculate the stress as [itex]4P/\pi d^2[/itex] (diameter d). At the end of the rod, the cross section is flattened into a rectangle, so the stress is [itex]P/wt[/itex] (width w, thickness t). BUT the width is reduced where material is cut out to fit the pin. At this cross section the stress is higher, [itex]P/(w-d)t[/itex]. Does this make sense?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook