Problem statement:
Need to perform a buckling analysis on a cyclonic separator stand. Create a metallic stiffener on the legs of the stand and run the analysis to find out the change in buckling factor of safety. The next step is to run a design study and find the optimum position for the stiffener. Compare the results for all the cases using tables and highlight the best one. You will need to make a report about your findings.
Aim:
- To perform the buckling analysis in the cyclonge seprator stand and to find the buckling factor of saftey.
- To design the stiffener on the legs of the stand of cyclone seprator.
- To run the buckling analysis to find the new buckling fos and to run a design study to find the optimum position fo the stiffener.
Introduction:
Cyclone seprator:
Principle and Working:
A high speed rotating (air)flow is established within a cylindrical or conical container called a cyclone. Air flows in a spiral pattern, beginning at the top (wide end) of the cyclone and ending at the bottom (narrow) end before exiting the cyclone in a straight stream through the center of the cyclone and out the top. Larger (denser) particles in the rotating stream have too much inertia to follow the tight curve of the stream and strike the outside wall, falling then to the bottom of the cyclone where they can be
removed. In a conical system, as the rotating flow moves towards the narrow end of the cyclone the rotational radius of the stream is reduced, separating smaller and smaller particles.
Applications:
General applications include:
_ oil refineries to separate oils and gases
_ cement industry
_vacuum cleaners
Features Required:
High efficiency over a broad flow range
Flow-optimized design
Low pressure drop resulting in energy savings
High safety during operation under pressure
Long-term corrosion protection
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.
A high speed rotating (air)flow is established within a cylindrical or conical container called a cyclone. Air flows in a helical pattern, beginning at the top (wide end) of the cyclone and ending at the bottom (narrow) end before exiting the cyclone in a straight stream through the center of the cyclone and out the top. Larger (denser) particles in the rotating stream have too much inertia to follow the tight curve of the stream, and thus strike the outside wall, then fall to the bottom of the cyclone where they can be removed. In a conical system, as the rotating flow moves towards the narrow end of the cyclone, the rotational radius of the stream is reduced, thus separating smaller and smaller particles. The cyclone geometry, together with volumetric flow rate, defines the cut point of the cyclone. This is the size of particle that will be removed from the stream with a 50% efficiency. Particles larger than the cut point will be removed with a greater efficiency, and smaller particles with a lower efficiency as they separate with more difficulty or can be subject to re-entrainment when the air vortex reverses direction to move in direction of the outlet.
Buckling:
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.
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.
Buckling analysis without the stiffener:
3d model:
orginal model as provided
Model analyzed
Model Information
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Model name: buckling_stiffner
Current Configuration: Default
|
|
Solid Bodies
|
|
Document Name and Reference
|
Treated As
|
Volumetric Properties
|
Document Path/Date Modified
|
|
No Support Cyclone Separator.STEP-1/Cyclone Stand.STEP-1-solid1
|
Solid Body
|
Mass:204.99 kg
Volume:0.0266221 m^3
Density:7700 kg/m^3
Weight:2008.91 N
|
|
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Study Properties
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Study name
|
Buckling 1
|
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Analysis type
|
Buckling
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Mesh type
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Solid Mesh
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|
Number of modes
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1
|
|
Solver type
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FFEPlus
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|
Incompatible bonding options
|
Automatic
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|
Thermal Effect:
|
On
|
|
Thermal option
|
Include temperature loads
|
|
Zero strain temperature
|
298 Kelvin
|
|
Include fluid pressure effects from SOLIDWORKS Flow Simulation
|
Off
|
|
Soft Spring:
|
Off
|
|
Result folder
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SOLIDWORKS document
|
|
Units
|
Unit system:
|
SI (MKS)
|
|
Length/Displacement
|
mm
|
|
Temperature
|
Kelvin
|
|
Angular velocity
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Rad/sec
|
|
Pressure/Stress
|
N/m^2
|
|
Material Properties
|
Model Reference
|
Properties
|
Components
|
| |
|
Name:
|
Alloy Steel
|
|
Model type:
|
Linear Elastic Isotropic
|
|
Default failure criterion:
|
Max von Mises Stress
|
|
Yield strength:
|
6.20422e+08 N/m^2
|
|
Tensile strength:
|
7.23826e+08 N/m^2
|
|
Mass density:
|
7700 kg/m^3
|
|
Elastic modulus:
|
2.1e+11 N/m^2
|
|
Poisson's ratio:
|
0.28
|
|
Thermal expansion coefficient:
|
1.3e-05 /Kelvin
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SolidBody 1(No Support Cyclone Separator.STEP-1/Cyclone Stand.STEP-1-solid1)(stand)
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|
Curve Data:N/A
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|
Loads and Fixtures
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Fixture name
|
Fixture Image
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Fixture Details
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|
Fixed-1
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|
|
Entities:
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4 face(s)
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|
Type:
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Fixed Geometry
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|
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Load name
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Load Image
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Load Details
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|
Force-1
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|
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Entities:
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1 face(s)
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Type:
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Apply normal force
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|
Value:
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150000 N
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|
|
Mesh information
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Mesh type
|
Solid Mesh
|
|
Mesher Used:
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Standard mesh
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|
Automatic Transition:
|
Off
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|
Include Mesh Auto Loops:
|
Off
|
|
Jacobian points
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4 Points
|
|
Element Size
|
18.282 mm
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|
Tolerance
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0.914099 mm
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|
Mesh Quality Plot
|
High
|
Mesh information - Details
|
Total Nodes
|
74739
|
|
Total Elements
|
39429
|
|
Maximum Aspect Ratio
|
7.2243
|
|
% of elements with Aspect Ratio < 3
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99.7
|
|
% of elements with Aspect Ratio > 10
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0
|
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% of distorted elements(Jacobian)
|
0
|
|
Time to complete mesh(hh;mm;ss):
|
00:00:10
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|
Computer name:
|
|
Study Results
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Name
|
Type
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Min
|
Max
|
|
Amplitude1
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AMPRES: Resultant Amplitude Plot for Mode Shape: 1(Load Factor = 9.34976)
|
0.000e+00
Node: 3593
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3.433e-03
Node: 1238
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buckling_stiffner-Buckling 1-Amplitude-Amplitude1
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Buckling factor of saftey for cyclone seprator without stiffner:
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Mode Number
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Load Factor
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1
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9.3498
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****************************************************************************************
Buckling analysis with the stiffener:
3d model:
original model of the cyclone seprator as provided:
Model used for simulation:
Model Information
|
Model name: buckling_stiffner
Current Configuration: Default
|
|
Solid Bodies
|
|
Document Name and Reference
|
Treated As
|
Volumetric Properties
|
Document Path/Date Modified
|
|
Boss-Extrude1
|
Solid Body
|
Mass:272.365 kg
Volume:0.0353721 m^3
Density:7700 kg/m^3
Weight:2669.18 N
|
|
|
Study Properties
|
Study name
|
Buckling 1
|
|
Analysis type
|
Buckling
|
|
Mesh type
|
Solid Mesh
|
|
Number of modes
|
1
|
|
Solver type
|
FFEPlus
|
|
Incompatible bonding options
|
Automatic
|
|
Thermal Effect:
|
On
|
|
Thermal option
|
Include temperature loads
|
|
Zero strain temperature
|
298 Kelvin
|
|
Include fluid pressure effects from SOLIDWORKS Flow Simulation
|
Off
|
|
Soft Spring:
|
Off
|
|
Result folder
|
SOLIDWORKS document
|
|
Units
|
Unit system:
|
SI (MKS)
|
|
Length/Displacement
|
mm
|
|
Temperature
|
Kelvin
|
|
Angular velocity
|
Rad/sec
|
|
Pressure/Stress
|
N/m^2
|
|
Material Properties
|
Model Reference
|
Properties
|
Components
|
| |
|
Name:
|
Alloy Steel
|
|
Model type:
|
Linear Elastic Isotropic
|
|
Default failure criterion:
|
Max von Mises Stress
|
|
Yield strength:
|
6.20422e+08 N/m^2
|
|
Tensile strength:
|
7.23826e+08 N/m^2
|
|
Mass density:
|
7700 kg/m^3
|
|
Elastic modulus:
|
2.1e+11 N/m^2
|
|
Poisson's ratio:
|
0.28
|
|
Thermal expansion coefficient:
|
1.3e-05 /Kelvin
|
|
SolidBody 1(Boss-Extrude1)(buckling_stiffner)
|
|
Curve Data:N/A
|
|
Loads and Fixtures
|
Fixture name
|
Fixture Image
|
Fixture Details
|
|
Fixed-1
|
|
|
Entities:
|
4 face(s)
|
|
Type:
|
Fixed Geometry
|
|
|
Load name
|
Load Image
|
Load Details
|
|
Force-1
|
|
|
Entities:
|
1 face(s)
|
|
Type:
|
Apply normal force
|
|
Value:
|
150000 N
|
|
|
Mesh information
|
Mesh type
|
Solid Mesh
|
|
Mesher Used:
|
Standard mesh
|
|
Automatic Transition:
|
Off
|
|
Include Mesh Auto Loops:
|
Off
|
|
Jacobian points
|
4 Points
|
|
Element Size
|
18.282 mm
|
|
Tolerance
|
0.914099 mm
|
|
Mesh Quality Plot
|
High
|
Mesh information - Details
|
Total Nodes
|
85364
|
|
Total Elements
|
44924
|
|
Maximum Aspect Ratio
|
7.2243
|
|
% of elements with Aspect Ratio < 3
|
99.5
|
|
% of elements with Aspect Ratio > 10
|
0
|
|
% of distorted elements(Jacobian)
|
0
|
|
Time to complete mesh(hh;mm;ss):
|
00:00:12
|
|
Computer name:
|
|
Study Properties
|
Study name
|
Design Study 1
|
|
Analysis type
|
Design Study(Optimization)
|
|
Design Study Quality
|
High quality (slower)
|
|
Result folder
|
SOLIDWORKS document
|
|
Units
|
Unit system:
|
SI (MKS)
|
|
Length/Displacement
|
mm
|
|
Temperature
|
Kelvin
|
|
Angular velocity
|
Rad/sec
|
|
Pressure/Stress
|
N/m^2
|
|
Design Study Setup
Design Variables
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Name
|
Type
|
Value
|
Units
|
|
offset
|
Range with Step
|
Min:500 Max:1500 Step:100
|
mm
|
Constraints
|
Sensor name
|
Condition
|
Bounds
|
Units
|
Study name
|
|
Buckling Factor of Safety1
|
is greater than
|
Min:27.000000
|
<ConstrUnits/>
|
Buckling 1
|
Goals
|
Name
|
Goal
|
Properties
|
Weight
|
Study name
|
|
Buckling Factor of Safety2
|
Minimize
|
Buckling Factor of Safety
|
10
|
Buckling 1
|
|
Study Results
13 of 13 scenarios ran successfully.
|
Component name
|
Units
|
Current
|
Initial
|
Optimal
|
Scenario1
|
Scenario2
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|
offset
|
mm
|
1000
|
1000
|
1000
|
500
|
600
|
|
Buckling Factor of Safety1
|
|
27.947567
|
27.947567
|
27.947006
|
19.438656
|
22.217762
|
|
Buckling Factor of Safety2
|
|
27.947567
|
27.947567
|
27.947006
|
19.438656
|
22.217762
|
|
Component name
|
Units
|
Scenario3
|
Scenario4
|
Scenario5
|
Scenario6
|
Scenario7
|
|
offset
|
mm
|
700
|
800
|
900
|
1000
|
1100
|
|
Buckling Factor of Safety1
|
|
25.597240
|
29.562424
|
31.570145
|
27.947006
|
24.178555
|
|
Buckling Factor of Safety2
|
|
25.597240
|
29.562424
|
31.570145
|
27.947006
|
24.178555
|
|
Component name
|
Units
|
Scenario8
|
Scenario9
|
Scenario10
|
Scenario11
|
<L_Iter5/>
|
|
offset
|
mm
|
1200
|
1300
|
1400
|
1500
|
<SR_Iter5/>
|
|
Buckling Factor of Safety1
|
|
21.022495
|
18.441469
|
16.306787
|
14.519378
|
|
|
Buckling Factor of Safety2
|
|
21.022495
|
18.441469
|
16.306787
|
14.519378
|
|
|
Observations:
- Buckling fos without stiffener is 9.3498
- Buckling fos is optimum when the stiffener is offset at 1000mm and having fos 27.947006
Conclusion:
- Buckling analysis is cattied without the stiffener and the buckling factor of saftery found is 9.3498.
- Buckling analysis design study is carried out with the stiffener and the optimum offset value is found to 100mm (Stiffener top surfacec to stand head bottom surface)
- Optimum fos value iwth stiffener is 27.947006
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