Simulation Study of a Bar Having Circular Cross Section Under Compressive Force

Intro: Simulation Study of a Bar Having Circular Cross Section Under Compressive Force

In this project i have used fusion 360 of auto desk.

I have made a bar having circular cross section.

Then I have applied a compressive force on it.

I have used model and simulation work space of fusion 360.

I have analysed the body for stress produced, strain produced, reaction force produced,

safety factor, and displacement.

I have used steel as a material for bar.

STEP 1: Sketching

In this step I am in the model work space of fusion 360.

Then I have drawn a circle on the top plane.

STEP 2: Extrusion

In this step I am in the model work space of fusion 360.

Then I have extruded the circle drawn in previous step.

STEP 3: Stress Analysis

In this step I am in the simulation work space of fusion 360.

Then I have fixed one end of the steel bar.

Then I have applied a compressive force of 500 N on the opposite face of

steel bar.

Then I have analysed the bar for stress produced.

The red color shows maximum value of stress.

The blue color shows minimum value of stress.

We can observe that the minimum value of stress is on the fixed side of the bar, but

around the longitudinal axis of bar.

The maximum value of stress is .06445 M Pa.

The minimum value of stress is .03021 M Pa.

STEP 4: Displacement Analysis

In this step I am in the simulation work space of fusion 360.

Then I have analysed the bar for the displacement produced.

The red color shows maximum displacement.

The blue color shows minimum displacement.

The maximum value of displacement is 8.753 E -05.

The minimum value of displacement is 0 mm.

We can see that minimum value of displacement is around fixed end.

We can also observe that maximum value of displacement is around free end.

STEP 5: Reaction Force Analysis

In this step I am in the model work space of fusion 360.

Then I have analysed the steel bar for the reaction force produced.

The red color shows the maximum value of reaction force .

The blue color shows the minimum value of reaction force.

We can observe that maximum reaction force is around the fixed end.

The value of maximum reaction force is 14.87 N .

The value of minimum reaction force is 0 N.

STEP 6: Strain Analysis

In this step I am in the simulation work space of fusion 360.

Then I have analysed the bar for the strain produced.

The red color shows maximum value of strain.

The blue color shows minimum value of strain.

The value of maximum strain is 4.123 E -07.

The value of minimum strain is 1.537 E -07.

Strain has no units because it is the ratio of two similar quantities.

STEP 7: Safety Factor

In this step i am in the simulation work space of fusion 360.

In this step I have provided the safety factor involved in this case.

The maximum value of safety factor is 15.

The minimum value of safety factor is 15.

Factor of safety is the ratio of maximum load and safe load.

Comments

[JamesT396]

I'd be a bit careful trusting these results. The stress / reaction force contours are obviously due to mesh discretization. I'm also fairly certain that the BCs are not what you really want. You state a force of 500 N on the top surface. Is that a point load, or distributed? Do you really want to fix the entire bottom face?

And finally, do you trust the safety factor you found? Why is it uniform if your stress field isn't?

I'm not trying to be too hard on you, but I'll finish with the question I always asked when I was teaching a FE course. Do your answers make sense? Assuming that this is supposed to be a purely compressive bar problem, this is a pretty simple problem with basic mechanics. Do a couple quick calculations to make sure your result is in the ballpark.

Finite element analysis is hard and it takes time to get it correct. Keep working and you'll get better!

[medanilevin]

Hey man
Nice first try.

You have really to refine the mesh.
And for simple case like this there are closed form solution. Circular bar in compression has uniform stress distribution, certainly on the outside where you look.
And if you compress bar with 500N, your reaction force is 500N. There is no way around it...

FYI, There is little value of obtaining solutions per node. It has no physical meaning.

And, I really want it to sound positive and constructive, it is the first advice I give my engineers: If you obtain results from FE code, they are not automatically right.

Dani

[dchesson93]

Did you fix the ring around the bar, or the end face of the bar? Your stress distribution for simple compression should be more uniform if the face was fixed, right?? The reaction force distribution (almost like honeycomb) looks a little strange to me, too. Maybe the mesh is to coarse?? The strange results seem to cluster around your mesh nodes.

[ankitthakur1998]

I have not fixed any ring around the bar. I have just turn off the visibility of the remaining portion of the bar and shown only that portion , which receives maximum and minimum stresses.

[dchesson93]

You have to have something that is fixed to have reactions like you are describing. And in simple compression, the results should look more uniform than they do. You shouldn't have a weird drop off in stress in the center of the face of the bar.

[ankitthakur1998]

As you will see all the images carefully than you can see this simulation correctly.

[dchesson93]

I had no idea 360 had simulation, though. I'll have to check it out and compare against Ansys to see what quality the results are!