Analysis of buckling phenomenon using FEA

When the lengthy beam is subjected to compressive axial stress, it tends to deflect sideways.

(When the structure is subjected to compressive stress, buckling may occur)

Buckling is an ability that leads to structural failure. Whenever a structure is subjected to compressive axial stress, buckling may occur. This may occur even if the applied stress is well below the stress needed to cause failure. As an applied axial load is increased on a member, such as a column, it will ultimately become large enough to cause the member to become unstable and it is said to have buckled. Further loading will cause significant and somewhat unpredictable deformations, possibly leading to complete loss of the member's load-carrying capacity.

here we are Import the cad model of cyclone seperator and supress all componets except seperator stand. Save the geometry as part file. Again open the part file and create a stiffner of thickness 70 mm at 1000 mm from top face without merging it with existing geometry.

case 1 : design for simulation of stand of cyclone separator without stiffener

first import the Cyclone separator file into Solidworks. It gets imported as an assembly, so suppress all the parts except the stand. (shown as fig 1) In the analysis, buckling analysis is selected, then click on New study select buckling study Rename the study-Analysis without stiffnerthen Click ok. here 'Alloy steel' is applied as material to the stand,(material properties shown as below) bottom faces of the columns are fixed, by selecting fixture geometry the load of '150000N' is applied on the plate above the columns (In compressive direction), Default mesh is applied (shownas fig 2) and the analysis is solved.

material properties

model type	linear elastic isotropic
material	Alloy steel
elastic modulus	210000 N/mm^2
possion ratio	0.28
shear modulus	79000 N/mm^2
mass density	7700 kg/m^3
tensile strength	723.8256 N/mm^2
yield strength	620.422 N/mm^2
thermal expansion coefficent	1.3e-0.5 /k
thermal conductivity	50 W/(m-k)

fig1(backling analysis of cyclone separator stand fig2(cyclone separator stand with mesh)

without stiffener)

fig3(final result - Amplitude plot)

buckling FOSof cyclone separator stand without stiffener

In case 1, without stiffener, we got the buckling factor of safety of 9.35 which is good (more than 1 is considered to be safe). and structure was much more reliably safe under the loading conditions as well as the critical load

fig2(cyclone separator stand with mesh)

Case 3: Parametric study to determine the optimum position for the stiffener.R

After completion of case 2, the Same simulation results are employed for design analysis.
It is carried out to determine the effect of the position of the stiffener (75mm thickness) along the length of the column on the buckling factor of safety.
Such that, the optimum position of the stiffener that gives the buckling factor of safety greater than 25

Defined Parameters:

1. Variables :Offet Distance: The stiffener was movedd axially from 0.25m to 1.75m through an increment of 0.25m from the datum(Ground level).

2.Constraints :Buckling Factor of safety: The minimum buckling FOS criteria was set as 25

3.Goal : Maximize the buckling factor of safety parameter.

The above inputs were given to the solver. The output of the design study is shown below.

conclusion :

As we can see from the above table the maximum buckling factor of safety is obtained at the offset distance of the stiffener is 1m, which is equal to 27.75 From the analysis conducted in three cases, the stand without the stiffener showed a buckling factor of safety of 9.35. Whereas the one with stiffener exhibited almost 3 times the FOS that is 27.75. The stiffener location was found to be optimal using a parametric design study and the design met the requirements of buckling FOS greater than or equal to 25.