Analysis of Buckling Phenomena

Aim : Perform a buckling analysis on a cyclonic separator stand . Create a metallic stiffener on the legs of the stand and run the analysis to find out the change in buckling factor of safety. The next step is to run a design study and find the optimum position for the stiffener. Compare the results for all the cases using tables and highlight the best one.

Introduction : There are two major categories leading to the sudden failure of a mechanical component: material failure and structural instability, which is often called buckling.

For material failures you need to consider the yield stress for ductile materials and the ultimate stress for brittle materials.

Structural failure : Loss of the load-carrying capacity of a component or member within a structure or of the structure itself. Structural failure is initiated when the material in a structure is stressed to its strength limit, thus causing fracture or excessive deformations.

Buckling is characterized by a sudden sideways failure of a structural member subjected to high compressive stress, where the compressive stress at the point of failure is less than the ultimate compressive stress that the material is capable of withstanding.

Basic theory on the simulation:

To perform buckling analysis:

• Create a buckling study. To access the Study dialog box, right-click the top icon in the Simulation study tree and select Study.
• Define material for each solid, shell, and beam. (in our case the stand of cyclone separator)
• Define restraints.
• Define loads.
• Mesh the model and run the study.
• View the results

Entire case setup:

1) Without Stiffner :

We have been provided by the cyclone separator assembly file.

Then , suppressed the file except the stand

Create a buckling study. To access the Study dialog box, right-click the top icon in the Simulation study tree and select Study.

Define material for each solid, shell, and beam. (in our case the stand of cyclone separator)

Define fixture , Leg of the stand.

Define force on top of the stand

Mesh the model and run the study.

Results:

In this case we got Buckling Factor of safety :

2). With Stiffner at 750mm distance from top plane:

Results:

In this Case , we got Buckling of Safety = 21.34

3). Design study and find the optimum position for the stiffener:

Defining Variables,constraints,Goals:

Results:

Conclusion :

As above observations ,

The Buckling Factor of safety without stiffener is 9.3941 .

and

The Optimum Buckling Factor of safety without stiffener is 27.933401 at 1000mm from the table top.