Assembly2 assembly meshing of boolion unioned parts min size .1 in or .05" in never seems to finish windows shows not re
Moderator: bernd
Forum rules
and Helpful information for the FEM forum
and Helpful information for the FEM forum
-
- Veteran
- Posts: 3129
- Joined: Sat May 20, 2017 12:06 pm
- Location: Germany
Re: Assembly2 assembly meshing of boolion unioned parts min size .1 in or .05" in never seems to finish windows shows no
Hi josheeg,
I did a "quick and dirty" cfd-run, to get a feeling what forces are
put on the tubes
profile: span=2500 mm, length 1100 mm, thickness 140 mm
windspeed: 10 m/s = 36 km/h
drag-x=2,15 N (which gives cd=0,1)
total lift 145 N (both wings produce 29 kg lifting force)
For each wing-tube you should use a load of 145/2 /2,5=29 N/m
perpendicular to the wind direction.
I did a "quick and dirty" cfd-run, to get a feeling what forces are
put on the tubes
profile: span=2500 mm, length 1100 mm, thickness 140 mm
windspeed: 10 m/s = 36 km/h
drag-x=2,15 N (which gives cd=0,1)
total lift 145 N (both wings produce 29 kg lifting force)
For each wing-tube you should use a load of 145/2 /2,5=29 N/m
perpendicular to the wind direction.
-
- Veteran
- Posts: 3129
- Joined: Sat May 20, 2017 12:06 pm
- Location: Germany
Re: Assembly2 assembly meshing of boolion unioned parts min size .1 in or .05" in never seems to finish windows shows no
When looking at the pressure-distribution, there should be an additional
Moment. The left tube gets more load then the right one.
But how to get the momentum in paraview?
Moment. The left tube gets more load then the right one.
But how to get the momentum in paraview?
Re: Assembly2 assembly meshing of boolion unioned parts min size .1 in or .05" in never seems to finish windows shows no
Wow impressive analysis.
I got the 98 in tube with carbon fiber material under 100 newtons abs deflection. Does when it turns red show it will break?
Or when will it show signs and wear? If red means it will break the next shorter tube may need to be used because when a kite is setup in crosswind and tethered it gets more forces on it I don't think the wikipedia equation is right but here is my one page. 70-90km/h at 7m/s wind.
I got the 98 in tube with carbon fiber material under 100 newtons abs deflection. Does when it turns red show it will break?
Or when will it show signs and wear? If red means it will break the next shorter tube may need to be used because when a kite is setup in crosswind and tethered it gets more forces on it I don't think the wikipedia equation is right but here is my one page. 70-90km/h at 7m/s wind.
Re: Assembly2 assembly meshing of boolion unioned parts min size .1 in or .05" in never seems to finish windows shows no
Freecad won't show you if it break.
From a material point of view, you're modeling a very simple material behaviour : linear elasticity.
It means that the stress rises lineary when the strain increases. The slope of this beahoviour law is the Young modulus you entered.
In your FEM calculation, you never gave a "max strain" or "max stress" value. So FC won't know it for you.
In your case, you have to know when the linear behaviour ends.
If you look this picture :
(taken from here : https://en.wikipedia.org/wiki/Stress%E2 ... rain_curve)
Your model is valid if you stay in the first linear part of the curve (in blue). If you excess (for your material) this area, you're simulation will be meaningless.
So, in your documentation, perhaps you have a linear elasticity limit ?
If you find a stress or strain limit, you'll have to look on your results to see if you've passed this limit or not.
From a material point of view, you're modeling a very simple material behaviour : linear elasticity.
It means that the stress rises lineary when the strain increases. The slope of this beahoviour law is the Young modulus you entered.
In your FEM calculation, you never gave a "max strain" or "max stress" value. So FC won't know it for you.
In your case, you have to know when the linear behaviour ends.
If you look this picture :
(taken from here : https://en.wikipedia.org/wiki/Stress%E2 ... rain_curve)
Your model is valid if you stay in the first linear part of the curve (in blue). If you excess (for your material) this area, you're simulation will be meaningless.
So, in your documentation, perhaps you have a linear elasticity limit ?
If you find a stress or strain limit, you'll have to look on your results to see if you've passed this limit or not.
Re: Assembly2 assembly meshing of boolion unioned parts min size .1 in or .05" in never seems to finish windows shows no
600 ksi is that a unit it is in tensle strength. They have data sheets at dragon plate.
Will it compare with my analysis?
Will it compare with my analysis?
Re: Assembly2 assembly meshing of boolion unioned parts min size .1 in or .05" in never seems to finish windows shows no
I see in the wikipedia article
"This stress is called the tensile stress because every part of the object is subjected to tension. The SI unit of stress is the newton per square meter, which is called the pascal.
1 pascal = 1 Pa = 1 N/m2"
So I should be looking for pascal or N/m^2?
"This stress is called the tensile stress because every part of the object is subjected to tension. The SI unit of stress is the newton per square meter, which is called the pascal.
1 pascal = 1 Pa = 1 N/m2"
So I should be looking for pascal or N/m^2?
Re: Assembly2 assembly meshing of boolion unioned parts min size .1 in or .05" in never seems to finish windows shows no
600 ksi to ~4k Mpa
shown in this online calculator.
Then I looked at some of the different analysis results mesh radio button options for stress and the max seems well below 4k Mpa so it should not break under loading?
shown in this online calculator.
Then I looked at some of the different analysis results mesh radio button options for stress and the max seems well below 4k Mpa so it should not break under loading?
Re: Assembly2 assembly meshing of boolion unioned parts min size .1 in or .05" in never seems to finish windows shows no
Yes, it seems to be right.
As a first approach, you can look a the von mises stress and put the max value to 4GPa (or 4 000MPa).
If you see anything red, it means the the stress exceed your max value and it might break.
You might have to think about a "safety factor". Just for an idea, you can say that your limit is 0.8*4100MPa = 3250 MPa.
I started to read some interesting thing here that explains quite clearly these notions : http://feaforall.com/calculate-safety-factor/
As a first approach, you can look a the von mises stress and put the max value to 4GPa (or 4 000MPa).
If you see anything red, it means the the stress exceed your max value and it might break.
You might have to think about a "safety factor". Just for an idea, you can say that your limit is 0.8*4100MPa = 3250 MPa.
I started to read some interesting thing here that explains quite clearly these notions : http://feaforall.com/calculate-safety-factor/
Re: Assembly2 assembly meshing of boolion unioned parts min size .1 in or .05" in never seems to finish windows shows no
- create a Vtk pipeline
- create a scalar filter
- set scalar clip options to van Mises stress
- set in result clip option to Surface with edges and van Mises stress
- set to your maximaum allowabalse stress
in the screen you see all nodes above 350 N/mm2 from the FEM 3D example and transparent all stresses.
- create a scalar filter
- set scalar clip options to van Mises stress
- set in result clip option to Surface with edges and van Mises stress
- set to your maximaum allowabalse stress
in the screen you see all nodes above 350 N/mm2 from the FEM 3D example and transparent all stresses.