Analysis of buckling phenomena

Aim :- To perform a buckling analysis on a cyclonic separator stand

Objective :-

• To perform a buckling analysis on a cyclonic separator stand
• To create a metallic stiffener on the legs of the stand and run the analysis to find out the change in buckling factor of safety.
• To run a design study and find the optimum position for the stiffener.
• To compare the results for all the cases using tables and highlight the best one

Theory :-

In engineering, buckling is the sudden change in shape of a structural component under load such as the bowing of a column under compression or the wrinkling of a plate under shear. If a structure is subjected to a gradually increasing load, when the load reaches a critical level, a member may suddenly change shape and the structure and component is said to have buckled.

Fig :- A column under a concentric axial load exhibiting the characteristic deformation of buckling

3D Model of cyclonic separator :-

• The first fig shows the model of a cyclone seperator
• Thus in this case we need to perform a buckling analysis on a cyclonic separator stand thus the fig 2 shows the stand on which the buckling analysis is carried out

Procedure :-

• For Case -1 Stand without stiffener
• Here in this case the test was conducted to find out the buckling factor of safety for the stand without the metallic stiffener
• The bottom face of the stand legs were made fixed
• Then the Alloy steel Material was selected for the stand
• The upper face was selected on which the 150KN load was applied
• The mesh level was selected as the fine mesh
• Next the setup was ran and results were obtained for amplitude
• The Buckling Factor of safety obtained in this case is 9.3677
• As the Buckling Factor of safety obtained in this case was too low so the case-2 study was implemented to obtain higher factor of safety by providing a stiffener
• The below snap shows the buckling in a stand without the stiffener also the animation shows how buckling occurs

https://youtu.be/Iwqr3I8NQw0

• For Case -2 Stand with a metallic stiffener
• Here in this case the test was conducted to find out the buckling factor of safety for the stand with a metallic stiffener
• The metallic stiffener was sketched as per the stand dimensions and was extruded as 75mm thick and was placed at an offset distance of 1000mm
• Now the bottom face of the stand legs were made fixed
• Then the Alloy steel Material was selected for the stand & Stiffener
• The upper face was selected on which the 150KN load was applied
• The mesh level was selected as the fine mesh
• Next the setup was ran and results were obtained for amplitude
• The Buckling Factor of safety obtained in this case is 27.805
• The factor of safety obtained in this case was much higher than the case 1 but it may go higher if the stiffener was placed at different offset so as to find it out the third case was implemented were the stiffener would be placed automatically at different offset level
• The below snap shows the buckling in a stand with a metallic stiffener also the animation shows how buckling occurs

https://youtu.be/0gjsR-YI_-Y

• For Case -3 Design Study for a Stand with Varying offset of metallic stiffener
• Here in this case the test was conducted to find out the buckling factor of safety for the stand with Varying offset of metallic stiffener
• The metallic stiffener was sketched as per the stand dimensions and was extruded as 75mm thick
• Next it was made to vary automatically by min 250mm offset value upto max 1750mm
• Thus this results in the seven different offset level
• Now the bottom face of the stand legs were made fixed
• Then the Alloy steel Material was selected for the stand & Stiffener
• The upper face was selected on which the 150KN load was applied
• The mesh level was selected as the fine mesh
• Next the setup was ran and results were obtained for amplitude
• The below snap shows the buckling in a stand with a varying offset of metallic stiffener

• The below snap shows the results of seven senarios for which the test was conducted
• The min offset length was set to 250mm
• The max offset length was set to 1750mm
• As change in the offset length the buckling factor also seems to be changing
• The below snaps shows the buckling of the stand for the seven different senarios

Result :-

• Thus we have studied the buckling analysis on a cyclonic separator stand
• ran the design study and found out the optimum position of the stiffener for which the buckling factor of safety is maximum

The below table shows the comparision of results for all the cases

	Case-1	Case-2	Case-3	Case-4	Case-5	Case-6	Case-7
offset Distance	250mm	500mm	750mm	1000mm	1250mm	1500mm	1750mm
Buckling factor of safety	12.6110	16.4841	22.3930	27.8047	20.8623	15.4400	11.8731

Conclusion :-

• It is observed that the factor of safety varies with change in the offset distance
• For the case 4 the buckling factor of safety seems to have highest value as 27.804
• Thus the optimum position of the stiffener should be as 1000mm as it gives the highest factor of safety value
• Thus the best suited case among all is the case 4