Analysis of buckling phenomena (Finite Element Analysis using Solidworks)

Abstract:-

For this project, the main objective is to carry out a buckling analysis on a Cyclonic separator stand. After the initial analysis, a metallic stiffener will be sketched and added to the stand and another buckling analysis will be simulated to find the change in the buckling Factor of Safety. Finally, a design study will be conducted to find the optimum position of the stiffener.

Introduction:-

Buckling is the failure mode of a structural member experiencing high compressive stresses that cause a sudden sideways deflection. Columns are usually subjected to buckling checks because compressive or axial forces are responsible for buckling and these are common in columns rather than beams, this is shown below in Figure 1.

Figure 1: an example of buckling

In many design projects, engineers must calculate the factor of safety (FOS) to ensure the design will withstand the expected loadings. this is a difficult task since the calculations require the exact values and mechanisms of failure. This is why engineers use an FEA technique known as Buckling analysis.

To begin the project, a Cyclonic Separator Stand was provided, Figure 2 shows the provided model.

Figure 2: The provided model of the stand

Since we are only analyzing the stand, the cyclonic separator will be suppressed.

Procedure 1:-

1. Apply the material to the stand (Alloy steel was chosen in both cases)
2. Apply fixtures and a load of 150,000N to the stand
3. Mesh the material 
4. Run the study and find the buckling FOS

Analysis:- 

1. Without Stiffener

Before starting the buckling analysis, the cyclonic separator was suppressed.

Figure 3: Three-dimensional model of the suppressed stand

Firstly, apply the material for the stand. Alloy steel was chosen as the material for this project for both analyses, Figure 3 highlights some of its properties.

Figure 4: Alloy Steel properties

The legs of the support were fixed for rigid support and a load of 150,000N was added to the stand as shown below in figure 7.

Figure 5: The fixtures and loads applied to the stand

Mesh:- 

The mesh parameters are shown in Figure 6, the mesh used was the same for both studies.

Figure 6: mesh parameters

Result:-

Figure 7 shows the buckling analysis study of the stand.

Figure 7: Final results of the stand

Figure 8 shows the buckling Factor of Safety of the stand.

Figure 8:Buckling FOS of the stand

Procedure 2:

A metallic stiffener was added to the stand that was used for Procedure 1, then the procedure is the same as the one used for Procedure 1 except a design study will also be conducted to determine the optimum position of the newly added stiffener. Figure 9 shows the added stiffener.

Figure 9: three dimensional model of the stand with the stiffener added

Analysis:-

The mesh parameters were the same as the one for procedure 1

Just like in procedure 1, the fixtures were placed below the legs for support and a load of 150,000N was placed on the stand as shown in Figure 10.

Figure 10: Loads and Fixtures are added to the new model

After adding the fixtures and loads, the new stand will undergo a mesh.

Figure 11: The meshed model of the new stand

After meshing the model, the study was run and the results are shown below.

Figure 12: The final results for the second study

The buckling Factor of Safety is also shown below in Figure 13.

Figure 13: Buckling FOS for the second study 

DESIGN STUDY:

A design study was conducted to determine the optimum position of the stiffener in the stand.  The studies were optimized to get the best results possible, to perform optimization the design variables must be defined. table 1 shows the defined variables.

Table 1: Variables of the design study

The next step for the design study is to define the constraints so that we can specify the conditions that your design must satisfy. The constraints can be driven by global variables or sensors for mass properties, dimensions, and simulation data. table 2 shows the defined constraints 

Table 2: Constraints of the designed study

The last step for specifying the parameters is to define the goals. Defining goals helps to specify your objective functions for the Optimization Design Study. 

Table 3: Goals of the designed study

After defining all the parameters, the number of scenarios (iterations) was 40, since SolidWorks starts with a "Current and Initial " study, the total amount of scenarios SolidWorks did was 42. (I have attached a link to the .xslx file for the design study data) ( ere.xlsx)

Results:-

The optimized design and values are shown below in Figures 14 and 15.

Figure 14: optimized design                                                                                         Figure 15: The optimum values

Conclusion:-

The buckling FOS of the stand without the stiffener is 9.3457, this is approximately three times lower than the FOS value of the stand with the stiffener which is 27.472, this means that the stiffener added additional strength and rigidity to the stand making it more reliable to be used in the industry.