Analysis of buckling phenomena in Solidworks

Abstract:-

In this project, the main objective is to perform a buckling analysis on a cyclonic separator stand by creating a metallic stiffener on the legs of the stand and run the analysis to find out the change in buckling factor of safety. Once we find the buckling factor of safety, we run a design study for different positions of the stiffener on the stand and find the optimum position for the stiffener and consider that buckling factor of safety

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.

Buckling refers to the loss of stability of a component and is usually independent of material strength. This loss of stability usually occurs within the elastic range of the material.

Fig. 1: Illustrates the buckling effect on the vertical beam when the load is applied.

Theory:-

Buckling may occur even though the stresses that develop in the structure are well below those needed to cause failure in the material of which the structure is composed. Further loading may cause significant and somewhat unpredictable deformations, possibly leading to complete loss of the member's load-carrying capacity. However, if the deformations that occur after buckling do not cause the complete collapse of that member, the member will continue to support the load that caused it to buckle. If the buckled member is part of a larger assemblage of components such as a building, any load applied to the buckled part of the structure beyond that which caused the member to buckle will be redistributed within the structure. Some aircraft are designed for thin skin panels to continue carrying load even in the buckled state.

In this study, I have used a cyclone seperator stand CAD(Downloaded from skill-Lync site).

Analysis:-

1. Performed a buckling analysis on the cyclone seperator stand without stiffner fig.2 illustrates the study

Fig. 2 3D model of cyclone seperator stand

Material Properties
Model type:	Linear elastic isotropic
Material:	Alloy Steel
Elastic Modulus:	2.1e+11 Nm−22.1e+11 Nm-2
Poisson's Ratio:	0.280.28
Shear Modulus:	7.9e+10Nm−27.9e+10Nm-2
Mass Density:	7700 kgm−37700 kgm-3
Tensile Strength:	723825600 kgm3723825600 kgm3
Yield Strength:	620422000 Nm−2620422000 Nm-2
Thermal Expansion Coefficient:	1.3e−05K−11.3e-05K-1
Thermal Conductivity:	50 Wm−1⋅K−150 Wm-1·K-1
Specific Heat:	460 J.kg−1⋅K−1460 J.kg-1·K-1

Steps to Analysis:-

1. Import the Cyclone separator file into Solidworks. It gets imported as an assembly, so suppress all the parts except the stand.
2. New study> choosing buckling study> Rename the study-Analysis without stiffner>Click ok.
3. Define the material used, which in our case is Alloy steel.
4. Fixtures to added. We fix the four bottom face of the legs of the cyclone seperator. Fig.3 Shows the fixture position
5. Externals Loads to defined: We add the force(N) on the top face of the cyclone seperator stand. Force applied: 150KN.
6. Mesh Parameter: Element size: 25 mm; Tolerance: 1.25 mm.

Fig.3: Analysis of Cyclone seperator without stiffner

Results:-

Fig.4: Results of analysis.

Buckling Factor of Safety is: 9.3669

Deformation Scale: 62.204

Analysis 2:-

In this analysis we will create a metallic stiffner(Alloy steel-Material) of 80mm in length as show in fig.5.

We initially run the buckling analysis similar to analysis_1, where stiffener is placed at a distance of 900mm and find the buckling factor of safety for it. This resulting factor of safety will use it as a base for our design study.

Fig.5. Before(1) and after(2) 3D model of stiffener inclusion

Steps to Analysis 2:-

1. Import the Cyclone separator file into Solidworks. It gets imported as an assembly, so suppress all the parts except the stand.
2. Use the face of the stand and sketch a square stiffener and extrude 80mm, post which, place the extruded part with offset function to around 900mm(Downwards direction). Fig.6. Shows the extruded part and dimensions
3. Choose New study> choosing buckling study> Rename the study-Analysis with stiffner>Click ok.
4. Define the material used, which in our case is Alloy steel.
5. Fixtures to added. We fix the four bottom face of the legs of the cyclone seperator. Fig.7 Shows the fixture position.
6. Externals Loads to defined: We add the force(N) on the top face of the cyclone seperator stand. Force applied: 150KN.
7. Mesh Parameter: Element size: 25 mm; Tolerance: 1.25 mm.

Fig.7. Analysis of Cyclone seperator with stiffner.

Results:

Fig.8: Results of analysis.

Buckling Factor of Safety is: 28.646

Deformation Scale: 58.117

3. Design Study.

The following conditions are involved in the design study.

1. Choose New Study> under that select design study.
2. Under design variable>select the offset distance of 900mm> ok> under value: Min: 100mm; Max:1900; Step: 200.
3. Under constraints> choose the simulation study> under that choose: Buckling factor of safety> ok> Condition:select-greater than.
5. Under goals> select Buckling factor of safety> Goal: Maximise.
6. Final Step is to run the simulation.Fig.9 : 12 Scenarios ran for design stud

Study Results:

From the design it is found from the first analysis that the buckling factor of safety for cyclone separator stand without support is 9.3669. In the design study it is obtained that the optimum position to place a stiffener is 900mm from the top of table and the maximum buckling factor of safety is approximately 28.646. The maximum buckling factor of safety is duly verified by the result of the design study.

Conclusion:

Hence the buckling factor of safety of the cyclone separator stand without support is 9.3669. The optimum position of stiffener to obtain maximum buckling factor of safety is 900mm from the table top. The maximum buckling factor of safety is approximately 28.646.