Can Mohr's Circle be Constructed with Only xx and yy Strain Values?

  • Thread starter Thread starter GBA13
  • Start date Start date
  • Tags Tags
    Circle Strain
Click For Summary

Discussion Overview

The discussion revolves around the construction of Mohr's Circle using strain values obtained from a strain rosette with two gauges positioned at 0 and 90 degrees. The primary concern is how to derive the xy strain component necessary for plotting the circle from the xx and yy strain values.

Discussion Character

  • Homework-related
  • Technical explanation

Main Points Raised

  • One participant expresses difficulty in finding the xy strain component needed for Mohr's Circle, having only obtained xx and yy strain values.
  • Another participant questions the relationship between the gauge orientations and the principal axes of strain, seeking clarification on this aspect.
  • A participant suggests that the gauges are aligned with the principal directions of strain, implying that the readings may represent principal strains.
  • There is a suggestion to consider the scenario as a simple, uniaxial stress in the x direction, which may influence the interpretation of the strain readings.

Areas of Agreement / Disagreement

Participants do not reach a consensus on how to derive the xy strain from the given values, and the discussion includes multiple viewpoints regarding the relationship between gauge orientation and principal strains.

Contextual Notes

There is uncertainty regarding the assumptions about the deformation and the implications of treating the scenario as uniaxial stress, which may affect the interpretation of the strain measurements.

GBA13
Messages
73
Reaction score
0

Homework Statement


I have used a strain rosette with two gauges at 0 and 90 degrees to find strain on a beam under force and an trying to plot Mohr's circle for the problem. As the gauges are at right angles finding the xx and yy strain is easy but I am lost about how to find the xy strain, which I need to plot the circle. How can I find xy from the xx and yy strain values?

Homework Equations

The Attempt at a Solution



I have got xx and yy but I honestly have no idea how to find xy[/B]
 
Last edited:
Physics news on Phys.org
How does the orientation of these gages relate to the principal axes of strain for this particular deformation? Do you know?

Chet
 
Chestermiller said:
How does the orientation of these gages relate to the principal axes of strain for this particular deformation? Do you know?

Chet

Hi Chet, I'm not sure how to tell to be honest! All I know is that the gauges are put on a long beam, one parallel to the edge of the beam and the other perpendicular and then the beam was forced downwards on the unsupported end.

I'm also told to think of it has a simple, uniaxial stress in x direction if that makes any difference.
 
Your gages are aligned with the principal directions. If you understand the kinematics of bending, then you will know why.

Chet
 
Oh OK. Does that mean that the readings on the gauges are the principle strains?
 
GBA13 said:
Oh OK. Does that mean that the readings on the gauges are the principle strains?
Sure..
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
8K
  • · Replies 8 ·
Replies
8
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K