9 Replies Latest reply on Jan 15, 2018 1:33 AM by Meyron Samuel

SIMMULATION ACCURACY

Meyron Samuel Jan 9, 2018 8:54 AM

WHEN I RUN A SIMPLE CANTILEVER BEAM I GET DIFFERENT RESULTS DEPENDING ON THE MESH DATA

IF I USE THE SMALLEST ELEMENTS I GET A MUCH BIGGER RESULT THAN MANUALLY CALCULATED

I DOUBLE CHECKED ALL THE DEFINITIONS AND I THINK I'M OK

?ANY SUGGESTIONS

!THANX

Re: SIMMULATION ACCURACY

Shaodun Lin Jan 9, 2018 9:01 AM (in response to Meyron Samuel)
Which result is bigger after the mesh size become smaller? Stress? Strain? Displacement?
Could you upload a picture to show the boundary conditions?
Like Show 1 Likes(1)

Actions
- Re: SIMMULATION ACCURACY
  
  Meyron Samuel Jan 9, 2018 9:11 AM (in response to Shaodun Lin)
  
  hi thanks for responding!
  the smaller the mesh elements are, the bigger the stress is
  
  Like Show 1 Likes(1)
  
  Actions
  - Re: SIMMULATION ACCURACY
    
    Meyron Samuel Jan 9, 2018 9:11 AM (in response to Meyron Samuel)
    
    Like Show 0 Likes(0)
    
    Actions
    - Re: SIMMULATION ACCURACY
      
      Meyron Samuel Jan 9, 2018 9:28 AM (in response to Meyron Samuel)
      
      as you can see the max stress is over 10 MPA and the calculated answer is 9 MPA
      
      Like Show 0 Likes(0)
      
      Actions
  - Re: SIMMULATION ACCURACY
    
    Shaodun Lin Jan 9, 2018 9:23 AM (in response to Meyron Samuel)
    
    Can you show the result with coarse mesh size?
    
    Like Show 2 Likes(2)
    
    Actions
Re: SIMMULATION ACCURACY

Shaodun Lin Jan 9, 2018 11:24 AM (in response to Meyron Samuel)

I guess the max stress is due to stress concentration at the sharp edge.

Hand calculation probably does not consider the effect of stress concentration
Like Show 3 Likes(3)

Actions
- Re: SIMMULATION ACCURACY
  
  Jon Dahlgren Jan 9, 2018 11:39 AM (in response to Shaodun Lin)
  
  A typical singularity as Shaodun describes.
  
  Edit: To clarify, a singularity is a numerical error where the solution tends to infinity with increased mesh resolution.
  
  Like Show 2 Likes(2)
  
  Actions
- Re: SIMMULATION ACCURACY
  
  Meyron Samuel Jan 15, 2018 1:33 AM (in response to Shaodun Lin)
  
  thank you for your time and answers!
  
  Like Show 0 Likes(0)
  
  Actions

Go to original post