### Strain Hardening Behavior Exercise - Solution Procedures

*General Concepts*: For a material with stress-strain behavior that can be described by

*s* = *K* *e*^{n}

a measure of the material strength is given by *K* and *n* describes how quickly the flow stress changes with strain.

What is the value of flow stress at strain = 1?

On the stress-strain plot a value of *n* can be set and different values of *K* tried. It will be seen that the value on the stress axis for strain = 1 is equal to the value of *K* chosen.

A more easily seen answer can be obtained by by setting a value for *K* and trying various values of *n*.

Which material parameter, *K* or *n*, has a larger effect on material strength?

Answering this question requires defining "strength" and deciding on a method for comparing values of strength. One possibility is to define strength as the flow stress at a particular value of strain and ask, does doubling the value of *K* or *n* have a larger effect on flow stress?

If the value of *K* is doubled, by how much does the flow stress change?

Since the flow stress depends on *K*, *n* and *e*, values of *n* and *e* have to be selected to determine the change when *K* is doubled? Several values of *n* and *e* have to be used to get a full picture of the effects.

If the value of *n* is halved, by how much does the flow stress change?

Again, flow stress depends on *K* and *e* as well as on *n* so the answer will vary with the values of *K* and *e* at which the comparison is made.

**Example answers are provided HERE**

**Back to Strain Hardening Exercise**

© 2001 by Barney E. Klamecki. All rights reserved