Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Calculating Nominal strain at which Necking Occurs

  1. Jan 13, 2010 #1
    1. The problem statement, all variables and given/known data
    Given two wires of guage length 100mm and 200mm
    They are loaded to fracture in tension
    The 100mm sample extends by 15mm
    The 200mm sample extends by 25mm.

    I need to use this information to calculate the nominal strain at which necking commences in the wires

    2. Relevant equations
    These are the relavent equations i can find in my notes relating to necking, stress/strain, true stress/strain

    we are also told, the true stress/strain curve generally represented by,

    where n is the work-hardening exponent

    "necking" in a sample started when the value of the true strain is equal to the work hardening exponent, i.e.,

    3. The attempt at a solution
    Im not so sure where to start with this as there are no forces given or areas. I assume we have to use the two sets of data to equated these terms and cancel them out.
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted