Finding Engineering Strain Just Before Yield for Wire w/ Modulus of Elasticity

In summary, the conversation discusses finding the engineering strain and corresponding true strain of a stretched wire, with the assumption that they are equal or close until necking occurs. The yield strength is approximated to be at the yield stress or proportionality limit. The issue lies in not having enough information about the modulus of elasticity, specifically the original and final lengths of the wire. It is mentioned that Young's modulus is another name for the modulus of elasticity and Hooke's law can be applied longitudinally. There is a question about the applicability of Hooke's law in the "longitudinal case".
  • #1
jabers
15
0
The engineering yield strength, the modulus of elasticity, the original diameter and final diameter of a wire are given. That wire is stretched and it diameter decreases. I am trying to find the engineering strain just before yield and the corresponding true strain.

So I assume I will find that the engineering strain is equal to or very close to the true strain because their curves don't diverge, in my experience, until necking occurs but I have to show that is the case. I believe that the yield strength is at the yield stress so a good approximation would be the proportionality limit.

My problem is that there are no specifics about the modulus elasticity. If it is young's modulus then I can find the lateral strain from hooke's law but then because I don't know the original or final lengths I don't know how to compare it to the true strain. Is there another law that I am forgetting about? Is hooke's law applicable for the longitudinal case?
 
Physics news on Phys.org
  • #2
Young's modulus is another name for the modulus of elasticity. Hooke's law applies longitudinally, in addition to other axes.
 
  • #3
What do you mean by the "longitudinal case"?
 

1. What is engineering strain?

Engineering strain is a measure of the deformation of a material relative to its initial length. It is calculated by taking the change in length of the material and dividing it by the original length.

2. How do you find the engineering strain just before yield?

To find the engineering strain just before yield, you need to measure the change in length of the material and divide it by the original length. This will give you the engineering strain value at that point.

3. What is the modulus of elasticity?

The modulus of elasticity, also known as Young's modulus, is a measure of a material's stiffness and its ability to resist deformation. It is the ratio of stress to strain within the elastic range of a material.

4. How is the modulus of elasticity related to engineering strain?

The modulus of elasticity is directly related to engineering strain. It is used to calculate the stress-strain curve of a material and is a key factor in determining the material's ability to withstand stress before yielding.

5. Why is it important to know the engineering strain just before yield?

Knowing the engineering strain just before yield is important because it helps engineers and scientists understand the behavior of a material under stress. It allows them to determine the material's maximum stress capacity and design structures that can withstand the expected levels of stress.

Similar threads

How to calculate elastic modulus
    • Engineering and Comp Sci Homework Help
2
Replies
53
Views
8K
Strain and Stress in Thin-Walled Hoops Under Pressure
    • Engineering and Comp Sci Homework Help
Replies
9
Views
2K
How Do You Calculate Elastic Modulus and Strengths from a Stress-Strain Curve?
    • Engineering and Comp Sci Homework Help
Replies
4
Views
2K
Young's Modulus of Elasticity Problems -
    • Engineering and Comp Sci Homework Help
Replies
33
Views
11K
Finding yield strength with modulus of elasticity
    • Engineering and Comp Sci Homework Help
Replies
1
Views
4K
What pressure would a strain of 40 µε indicate?
    • Engineering and Comp Sci Homework Help
2
Replies
61
Views
12K
Unraveling the Stress-Strain Curve: Find Young's Modulus & Yield Strength
    • Engineering and Comp Sci Homework Help
Replies
7
Views
7K
Using Stress/Strain Curve to Find Yield Strength and Modulus of Elasticity
    • Engineering and Comp Sci Homework Help
Replies
6
Views
87K
Young's modulus, stretching question.
    • Engineering and Comp Sci Homework Help
Replies
2
Views
2K
What is the origin and validity of assumptions about the strain energy function?
    • Mechanical Engineering
Replies
8
Views
1K

Hot Threads

Recent Insights

Back
Top