(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

"The axial load for a given test sample carries 1590 N. Calculate tensile stress at sections (1) and (2) assuming the sample thickness is 5mm. (Rectangular cross section).

http://img208.imageshack.us/img208/121/tensilestressby1.th.jpg [Broken]

2. Relevant equations

normal stress = P/A

Pallow = (normal stress)allow * A

3. The attempt at a solution

This is a new one for me. All the previous homework problems involved a prismatic bar (a bar of uniform cross-section) and not this 'necked' bar.

Since P are pulling forces, the bar is in tension.

I know my first step would be to convert 5mm into meters = 0.005m

But then I'm sorta lost.

Do I just use the normal stress equation above for each section; 1 and 2? Keeping P = 1590N and then changing A for section 1 to 30mm = 0.03m, and for section 2 to 10mm = 0.01m?

But then where does 5mm come into play?

Thanks for all the help.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Axially Loaded Member and Tensile Stress oh so lost

**Physics Forums | Science Articles, Homework Help, Discussion**