- #1

Feodalherren

- 605

- 6

## Homework Statement

1.The maximum energy (per unit volume) that can be absorbed by the steel alloy without

sustaining permanent deformation is _______ lb/in^2

1.4. The maximum energy (per unit volume) that can be absorbed bythe steel prior to fracturing is _______ kip/in^2.

.

## Homework Equations

## The Attempt at a Solution

If I remember correctly, stored energy is the area under the graph.

Since I don't know the equation I will work with estimates.

First, I used the 0.2 % offset method to find the Yield strength of the material and I found the yield strength to be about 65 ksi.

The area under the straight line is (1/2)(.002)(60E3)=60

I estimate the rest of the area as a rectangle: (0.002)(60)=120

which gives a grand total of 180 lb/in^2.

Yet the solution, which is not worked out, claims that the energy is only the first part, namely 60 lb/in^2. I thought a material wouldn't be deformed before it gets to the point of yield strength, and in the previous step I found the yield strength correctly. I'm thinking they did something wrong because the solution even goes on to say "Modulus of resilience"=60PSI.

1.4 should just be the same thing, total area under curve?