Getting a Feel For Buckling

One of the various study types available within Simulation Professional, Buckling, is a very important aspect of our analysis looking at the strength of parts and determining how they are in danger of failing.

To give you a better sense of how important a buckling test can be, you can perform your own quick demo based on a lab I remember from college. This used a simple process to demonstrate the principles of buckling well and gave me a feel for how catastrophic buckling failure can be.

Find an empty 12 oz. soda can, and make sure there are no dents in the side. It is important that the can not be previously damaged. The idea here is to gradually apply more and more force to the top of the can while it sits on the ground until it reaches the critical load at which buckling will occur. At this point you will experience the rapid failure as the side wall of the can collapses. I usually add the load by placing one foot on the can and shifting my weight until the can buckles, but I will say to be careful with this and be sure to wear shoes because though I’ve never had an issue, I don’t want anyone to hurt themselves trying this.

I really enjoy the experience of this demo, as you can feel how the gradual application of increased weight has no effect until the critical load is reached at which point, rapid and total failure occurs.

As a comparison, you can test the load required to buckle a can with some dents in the side wall and see how the critical load is significantly reduced. Depending on the severity of the dent, it can even induce immediate plastic bending rather than buckling failure.

Before: After Buckling:

CokeCan_normal CokeCan_crushed

Within SolidWorks, we can run a buckling study to identify the buckling factor of safety for our part or assembly to determine whether we are in danger of buckling. If the BFS exceeds that of our stress analysis, then we know that buckling is not the primary governing phenomenon.

Here is an example of a buckling study run on a Particle Separator assembly where we can clearly see the first buckling mode behavior. In the second view I have the deflection showing scaled up by 2 to clearly identify how this assembly buckles.

Loading and Fixtures: Buckling Analysis:

Buckling_3 Buckling_1

Checking the factor of safety for this study gives the BOS to be: 21.2 which exceeds the factor of safety calculated in the stress analysis of 9. So in this case, we know that the assembly will fail prior to reaching the critical load at which buckling would have occurred.

I hope you enjoy experiencing buckling as I have, and fully appreciate the importance of this test as part of our analysis.