8 Replies Latest reply on Feb 17, 2017 10:08 AM by Julien Boissat

sn curves based on the moduli of elasticity

Alan McLaughlin Jan 12, 2016 5:35 PM

Hi,

I'm trying to run a fatigue study using alloy 356 T6 as a material.

I've had no luck tracking down an SN curve but Solidworks allows deriving the SN curve automatically based on ASME SN curves and the moduli of elasticity based on ASME Carbon Steel curves or Austentic Steel curves.

So my question is: will the curve derived be of any use as it is based on steel and my material is aluminium?

Thanks in advance

Re: sn curves based on the moduli of elasticity

Janko Stellaard Jan 13, 2016 8:34 AM (in response to Alan McLaughlin)

Hi Alan,

According to SW Help:

The SN curve is derived by dividing each stress value of the reference SN curve by the modulus of elasticity of the reference ASME material and multiplying it by the modulus of elasticity of the current material. The associated numbers of cycles remain unchanged.

I would try to compare it to a Aluminum material that you know a SN curve and E-mod off. It will answer your question.

Janko Stellaard
Cadmes BV
The Netherlands
Like Show 0 Likes(0)

Actions
- Re: sn curves based on the moduli of elasticity
  
  Alan McLaughlin Jan 13, 2016 5:23 PM (in response to Janko Stellaard)
  
  Hi Janko,
  
  thank you very much for your help.
  
  Could you expand on the phrase 'E-mod off'?
  
  Thanks in advance
  
  Alan
  
  Like Show 0 Likes(0)
  
  Actions
Re: sn curves based on the moduli of elasticity

James Riddell Jan 13, 2016 3:25 PM (in response to Alan McLaughlin)

http://www.engineeringbookstore.com/smeb/Materials/AtlasFatigue.htm
Like Show 0 Likes(0)

Actions
- Re: sn curves based on the moduli of elasticity
  
  Alan McLaughlin Jan 14, 2016 2:33 PM (in response to James Riddell)
  
  Thank you James.
  
  Like Show 0 Likes(0)
  
  Actions
Re: sn curves based on the moduli of elasticity

Julien Boissat Jan 13, 2016 6:25 PM (in response to Alan McLaughlin)

Hello,

The answer is no, you shouldn't.
Please refer to Solution S-069698 from the SOLIDWORKS Knowledge Base.
Excerpt: "The "Derive from material Elastic Modulus" option is ONLY valid for the fatigue validation (according to the ASME code) of BOILERS AND PRESSURE VESSELS made of material approved by the ASME CODE for such use."

Julien BOISSAT
Expert, Technical Customer Support - SOLIDWORKS Simulation
3DS.COM/SOLIDWORKS
Dassault Systèmes
Like Show 0 Likes(0)

Actions
- Re: sn curves based on the moduli of elasticity
  
  Alan McLaughlin Jan 14, 2016 2:33 PM (in response to Julien Boissat)
  
  Thank you Julien, it's good to get a definite answer for future reference.
  
  Like Show 0 Likes(0)
  
  Actions
- Re: sn curves based on the moduli of elasticity
  
  Sivateja Kasireddy Feb 15, 2017 11:24 PM (in response to Julien Boissat)
  
  Do you know that particular ASME code. I need to use that as a reference in my project.
  
  Like Show 0 Likes(0)
  
  Actions
  - Re: sn curves based on the moduli of elasticity
    
    Julien Boissat Feb 17, 2017 10:08 AM (in response to Sivateja Kasireddy)
    
    See Shop for Engineering Standards from the ASME web site.
    
    Like Show 1 Likes(1)
    
    Actions

Go to original post