Analysis of Buckling Phenomena using SolidWorks

Finite Element Analysis of Buckling Phenomena on a Cyclonic Seperator Stand using Solidworks

Introduction

BUCKLING

• Buckling is an instability that leads to structural failure. The failure modes can in simple cases be found by simple mathematical solutions. For complex structures the failure modes are found by numerical tools.
• When a structure is subjected to compressive axial stress, buckling may occur.
• Buckling is characterized by a sudden sideways deflection of a structural member. This may occur even though the stresses that develop in the structure are well below those needed to cause failure of the material of which the structure is composed. 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. 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.

Slenderness Ratio​

• The Slenderness Ratio, or simply Slenderness is the quotient between the width of a Structure and its height.
• Slenderness is a measure of the propensity of a column to buckle. It is defined as where l is the effective length of the column and is the least radius of gyration.
• Least radius of Gyration defined by where is the area of the cross-section of the column and is the second moment of area of the cross-section.
• This ratio is critical in finding the failure modes in the Columns.

Cyclonic Seperator

• Cyclone separators or simply cyclones are separation devices that use the principle of Inertia to remove Particulate matters from flue gasses.
• Cyclone separators work much like a centrifuge, but with a continuous feed of dirty air. In a cyclone separator, dirty flue gas is fed into a chamber. The inside of the chamber creates a spiral vortex, similar to a tornado.

Area of Interest : Cyclonic Seperator Stand

Since in this study we are performing Buckling Analysis on the Stand Columns, lets Exclude all other parts from the Analysis.

Objective :

To perform Buckling Analysis on the above Stand and also perform a Buckling Analysis to the same by constructing a Stiffener across the Columns and also to evaluate for the Parameteric Design Study to Optimize for position of Stiffener.

Material Properties :- Alloy Steel

Pre Conditions :

• Material is Alloy Steel
• Type of Analysis :- Buckling
• 4 Columns are fixed to ground.
• load acts on plate surface at top.

Case 1 :- Buckling Analysis on the Stand with No Stiffener.

• Applied Load on Surface = 1,50,000 N

Result

• In the above case, for the load applied the Buckling FOS = 9.3672
• The Stand can withstand a load which is nearly 9 times more than the applied load.
• Since FOS is considerably more than 3 in this case, the stand can be termed as safe to the applied load.

Case 2 :- Buckling Analysis on the Stand Stiffener at an Arbitrary Position.

In this case an stiffener of 75mm thickness is constructed across the legs and at an height of 1000 mm from the loading surface.

And same load of 150000 N is applied after Fixing the supports and Meshing the Structure for Buckling Analysis.

Result

• In the above case, for the load applied the Buckling FOS = 26.789
• The Stand can withstand a load which is nearly 27 times more than the applied load.
• Since FOS is considerably more than 3 in this case, the stand can be termed as safe to the applied load.
• Also by adding the Stiffener the load carrying capacity of the Stand is increased almost by 3 times.

Case 3 :- Parametric Design Study/Design Optimization

• In this case Design Optimization is performed to check for the optimal position of the Stiffener and the thickness of the stiffener for the load carrying capacity of Stand.
• Design Study is the tool which helps to perform Parametric evaluation in Solidworks
• Variables such as distance from loading surface to stiffener, thickness of stiffener and their range can be added
• Constraints such as the maximum Stress, minimum load carrying Capacity, min FOS can be defined to achieve Optimization
• Goals can be defined to select the best result from the list of optimized solutions.

Design Study Inputs

Based on the inputs and constraints provided the parametric study calculates the Permutations possible and check for each evaluation for the possible optimization.

350 Combinations were trailed and an optimized solution based on goal will be obtained.

Results

Parametric Study

Optimized Solution

• In the above case, for the load applied the Buckling FOS = 31.64
• The Stand can withstand a load which is nearly 32 times more than the applied load.
• Since FOS is considerably more than 3 in this case, the stand can be termed as safe to the applied load.
• Maximum Load carrying capacity is obtained with the stiffener of 100mm thickness, and placed at distance of 900mm from the loading surface.

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