Shear Stress of a particular length rod

Click For Summary

Discussion Overview

The discussion revolves around the yield strength of stainless steel and its application to a specific rod with given dimensions. Participants explore the relationship between shear stress, rod length, diameter, and cross-sectional area, as well as the implications of these factors on material properties.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions whether the yield strength value of 520 MPa for stainless steel is based on a specific geometry, such as a cube.
  • Another participant asserts that stress is independent of the length of the rod and only depends on the cross-sectional area.
  • A participant seeks clarification on the specific cross-sectional area related to the stress values and whether the shape of the rod affects these values.
  • One participant notes that calculating deformation requires applied stress, mechanical properties, and geometry, suggesting that the Young's modulus and geometry are essential for further analysis.
  • Links to external resources are provided to assist in understanding the calculations related to beam deformation.
  • A participant mentions that the aspect ratio of the rod may influence the applicability of certain approximations for thin beams.

Areas of Agreement / Disagreement

Participants express differing views on the relevance of rod length to yield strength and the interpretation of stress values, indicating that multiple competing views remain without a consensus.

Contextual Notes

There are unresolved questions regarding the dependence of stress on cross-sectional area and shape, as well as the specific conditions under which the yield strength applies. The discussion does not clarify these dependencies fully.

pukey123
Messages
4
Reaction score
0
Just a quick question:

Wikipedia tells me that due the shearing stress, the yeild strength of Stainless Steel is 520Mpa

But how can i find out the Yeild strength of a 100mm long rod with diameter 10mm.

Is the info for wikipedia based on a 1mx1mx1m cube? or some sort of SI unit.

Cheers
 
Last edited:
Physics news on Phys.org
The stress doesn't depend on the length of the rod - it only depend son the cross section area.
Mpa is mega pascal - is a unit of pressure, 1 pa is one Newton/m^2
So 1Mpa is around 100,000 Kg/m^2, or 145psi
 
i see, but the what cross section area are the stresses relating to? and does it also depend on the shape?

If i see the value of 520MPA in a book for s steel, how can i use that to aplly it to a rod with a given diameter?
 
Calculating the deformation of a rod requires three things- the applied stress, the mechanical properties of the rod, and the geometry of the rod. All you have right now is (I'm guessing) the Young's modulus for a particular type of stainless steel and the geometry of the rod.

Try surfing through these, see if it helps:

http://www.clag.org.uk/beam-menu.html
http://www.mhhe.com/engcs/engmech/beerjohnston/mom/lectureppt.mhtml
http://www.grantadesign.com/resources/shapes/solutions/elastic.htm

Note- thin beams have a simple approximate solution. Yours, with an aspect ratio of 10, may or may not be amenable to that approximation.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
1K
Replies
2
Views
3K
Replies
3
Views
10K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
9K
  • · Replies 78 ·
3
Replies
78
Views
7K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
4
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K