Analysis of buckling phenomena
Objective: To perform a buckling analysis on a cyclonic separator stand
Problem Statement:
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.
Theory:
Buckling of Columns is a form of deformation as a result of axial-compression forces. This leads to bending of the column, due to the instability of the column. This mode of failure is quick, and hence dangerous. Length, strength and other factors determine how or if a column will buckle. Long columns compared to their thickness will experience elastic buckling similar to bending a spaghetti noodle. This will occur at stress level less than the ultimate stress of the column.
Euler’s theory of column buckling is used to estimate the critical buckling load of column since the stress in the column remains elastic. The critical buckling load is the maximum load that a column can withstand when it is on the verge of buckling. The buckling failure occurs when the length of the column is greater when compared with its cross-section.
The Euler’s theory is based on certain assumptions related to the point of axial load application, column material, cross-section, stress limits, and column failure. The validity of Euler’s theory is subjected to a condition that failure occurs due to buckling.
Failure of the column would occur in purely axial compression provided that the stress in the column reaches the yield stress of the material. However, when the critical buckling stress is less than the yield stress, then the column would fail by buckling before the yield stress is reached.
Study Setup:
No Stiffener
Create a Case Study, use the existing part given and open it using Solidworks, and exclude the components using exclude from the analysis option of the Study Setup.
Apply Alloy Steel Material as shown below.
Use the fixture option to fix the 4 legs of the stand.
Then add the force on the top of the stand as shown.
Create a mesh of the desired refinement and use the mesh and run option to get the results.
The heat map below displays how the stresses act on the stand.
The Buckling factor of safety is displayed below.
With Stiffener
Follow similar steps to open the part in Solidworks and exclude the components which are not necessary using the suppress option in the parts.
Then create the following dimensions on the top plane.
Then extrude using the following properties.
Use the study option to create a Buckling Study as done earlier. Repeat the steps by applying the material, fixing the legs, applying the load, creating the mesh and then run it.
The results obtained are:
The Buckling factor of safety is displayed below.
Create a Design Study
Then add the Offset, min, max, and step values in the Variables option mentioned.
Then for the constraints, the following is selected.
The Goals are also added and in the end, the input parameters are shown mentioned below.
Results:
The results for the study are mentioned below
We can gauge from the results that 1m is the most optimal offset position as pointed out after the simulation. It is the only position where the value crosses the criteria mentioned which is the buckling factor being greater than 25 and it also remains to be the maximum value amongst all the scenarios.
Conclusion:
So, we can conclude that the stiffener being positioned at a distance of 1m from the top accounts for a more safe design compared to the other results where the solution doesn't get close to the desired value.
The Simulation for buckling analysis on a cyclonic separator stand is successfully completed and the required results are plotted.
References:
https://civildigital.com/buckling-columns-euler-theory-elastic-buckling/
https://theconstructor.org/structural-engg/euler-theory-column-buckling/37341/