Normal Stress Help: Find Normal Stress for 15kN & 20kN Plate of AISI 1010 Steel

[x31fighter]

Homework Statement

A 12cm X 12 cm square plate of AISI 1010 steel (E=200 GPa) us subjected to normal tensile forces of 15 kN and 20 kN on the top and right edges as shown in figure P22. The thickness of the plate is 5mm, and the left and bottom edges of the plate are fixed. Find the normal strain and deformation of the plate in the horizontal and vertical directions.

Homework Equations

Normal Stress = P/A

The Attempt at a Solution

I am not asking for help for the entire problem just help finding the normal stress for one.
I am assuming P is Pascals, so I believe that P is the same Newtons? 15kN = 15000N = 15000P
Is that part correct?
Then I would just divide that by the area 144 cm.

 

[anathema]

Yes, your assumption is correct. P represents normal force in Newtons and you can convert 15 kN to 15000 N. However, the area should be in square meters, not square centimeters. So you need to convert the given dimensions of the plate from centimeters to meters, which would be 0.12 m x 0.12 m = 0.0144 m^2. Then you can use the formula for normal stress to find the stress on the top edge, which would be 15000 N/ 0.0144 m^2 = 1.04 MPa. Repeat the same process for the right edge, using the force of 20 kN.