Buckling Analysis of The Cyclone Separator Stand

AIM: Perform buckling analysis on cyclone separator and find out best position for stiffener by performing a design study.

OBJECTIVES:

• Perform buckling analysis on a cyclone separator stand.
• Create a metallic stiffener on the stand and perform buckling analysis to find buckling factor of safety.
• Perform design study to find out optimum position for the stiffener.
• Compare all the results and choose the best position for the stiffener.

THEORY:

Cyclonic separation is a method of removing particulates from an air, gas or liquid stream, without the use of filters, through vortex separation. When removing particulate matter from liquid, a hydrocyclone is used; while from gas, a gas cyclone is used. Rotational effects and gravity are used to separate mixtures of solids and fluids. The method can also be used to separate fine droplets of liquid from a gaseous stream.

Stiffeners are secondary plates or sections which are attached to beam webs or flanges to stiffen them against out of plane deformations.

Almost all main bridge beams will have stiffeners. However, most will only have transverse web stiffeners, i.e. vertical stiffeners attached to the web. Deep beams sometimes also have longitudinal web stiffeners. Flange stiffeners may be used on large span box girder bridges but are unlikely to be encountered elsewhere.

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.

Eigenvalue buckling analysis is generally used to estimate the critical buckling (bifurcation) load of structures. The analysis is a linear perturbation procedure. The analysis can be the first step in a global analysis of an unloaded structure or it can be performed after the structure has been preloaded. It can be used to model measured initial overall and local geometric imperfections or in the investigation of the imperfection sensitivity of a structure in case of lack of measurements. Eigenvalue buckling is generally used to estimate the critical buckling loads of stiff structures (classical eigenvalue buckling). Stiff structures carry their design loads primarily by axial or membrane action, rather than by bending action. Their response usually involves very little deformation prior to buckling.

Factor of safety, also known as safety factor, expresses how much stronger a system is than it needs to be for an intended load. Safety factors are often calculated using detailed analysis because comprehensive testing is impractical on many projects, such as bridges and buildings, but the structure's ability to carry a load must be determined to a reasonable accuracy. Many systems are intentionally built much stronger than needed for normal usage to allow for emergency situations, unexpected loads, misuse, or degradation.

PROCEDURE:

Modelling

A stiffener of 75mm extrude is provided at the distance of 1m from the top plane.

Simulation

Mesh Slider is adjusted slightly between middle and fine.

Design Study

Variable->Add Parameter->Stiffener Distance->Range with step

Min – 250mm Max – 1750mm Steps – 250mm

Constraints->Buckling factor of safety -> is greater than -> min:25 -> Stand Buckling Analysis (Buckling Analysis Name)

Goals->Buckling factor of safety->Maximize-> Stand Buckling Analysis (Buckling Analysis Name)

Run.

RESULT:

Simulation

Factor of safety

The factor of safety for our stand is 12.265 which means that the stand will buckle when we apply force which 12 time more than our current applied force i.e. 150KN. In other words, the stand will buckle when 150*12=1800KN force is applied.

Design Study

From the above table we can clearly observe the maximum factor of safety is obtained when stiffener is offset at 1000mm or 1m distance from the top face. When stiffener is offset at 1000m/1m the stand will buckle when 41,61KN force is applied. Thus, 1000mm/1m offset is the optimal design for our stand.

CONCLUSION:

By comparing all the results, it is concluded that the 1000mm/1m offset is the optimal design for the cyclone separator stand.