Chapter 7 Design Analysis .......................................................................................(58-90)
7.3 Fatigue Analysis
DESIGN ANALYSIS
CHAPTER
58
59 Taken at the output coordinate system.
πΌπ₯π₯ = 2.19π + 007πΌπ₯π¦ = 4.45π + 004πΌπ₯π§ = β1.15π + 005 πΌπ¦π₯ = 4.45π + 004πΌπ¦π¦ = 5.05π + 006πΌπ¦π§ = 1.65π + 006 πΌπ§π₯ = β1.15π + 005πΌπ§π¦ = 1.65π + 006πΌπ§π§ = 2.53π + 007
Figure 7-1: Location of Origin and COM Design Analysis
60
7.2 Stress and Strain Analysis
Analysis Condition:
Fixed geometry: Foot Base
External Force: 0.2 Newton Force Acting On L-Bracket Each Gravitational Force: 9.81 m/s2
Figure 7-2: Analysis Setup - Fixed Geometry (Foot Base) and External Load on Waist and Gravitational Force Acting on Body
Design Analysis
61
Table 7-1: Model Information
Document Name and
Reference Treated As Volumetric Properties Extrude11
Solid Body
Mass: 0.0435692 kg Volume: 3.11208e-005 m^3 Density: 1400 kg/m^3 Weight: 0.426978 N
Cut-Extrude1
Solid Body
Mass: 0.0150493 kg Volume: 5.57383e-006 m^3 Density: 2700 kg/m^3 Weight: 0.147483 N
CirPattern2
Solid Body
Mass: 0.0112408 kg Volume: 4.16326e-006 m^3 Density: 2700 kg/m^3 Weight: 0.11016 N
Design Analysis
62
Table 7-2: Static Study
Study name Study 1
Analysis type Static
Mesh type Mixed Mesh
Thermal Effect: On
Thermal option Include temperature loads Zero strain temperature 298 Kelvin
Include fluid pressure effects from SolidWorks Flow Simulation
Off
Solver type FFEPlus
Inplane Effect: Off
Soft Spring: Off
Inertial Relief: Off
Incompatible bonding options Automatic
Large displacement Off
Compute free body forces On
Friction Off
Use Adaptive Method: Off
Table 7-3: Unit System
Unit system: SI (MKS)
Length/Displacement mm
Temperature Kelvin
Angular velocity Rad/sec
Pressure/Stress N/m^2
Design Analysis
63
Model Reference Properties Components
Name: 1060 Alloy Model
type:
Linear Elastic Isotropic Default
failure criterion:
Unknown
Yield strength:
2.75742e+007 N/m^2
Tensile strength:
6.89356e+007 N/m^2
Elastic modulus:
6.9e+010 N/m^2 Poisson's
ratio:
0.33 Mass
density:
2700 kg/m^3 Shear
modulus:
2.7e+010 N/m^2 Thermal
expansion coefficient:
2.4e-005 /Kelvin
SolidBody 1(Sketched Bend1)
(Bracket servo single_-10), SolidBody 1(Sketched Bend1)
(Bracket servo single_-11), SolidBody 1(Sketched Bend1)
(Bracket servo single_-12), SolidBody 1(Sketched Bend1)
(Bracket servo single_-13), SolidBody 1(Sketched Bend1)
(Bracket servo single_-14), SolidBody 1(Sketched Bend1)
(Bracket servo single_-15), SolidBody 1(Sketched Bend1)
(Bracket servo single_-16), SolidBody 1(Sketched Bend1)
(Bracket servo single_-17), SolidBody 1(Sketched Bend1)
(Bracket servo single_-18), SolidBody 1(Sketched Bend1)
(Bracket servo single_-19), SolidBody 1(Sketched Bend1)
(Bracket servo single_-3), SolidBody 1(Sketched Bend1)
(Bracket servo single_-4), SolidBody 1(Sketched Bend1)(Bracket servo single_-5),
SolidBody 1(Sketched Bend1)
(Bracket servo single_-6), SolidBody 1(Sketched Bend1)
(Bracket servo single_-7),
Design Analysis
64
SolidBody 1(Sketched Bend1)
(Bracket servo single_-8), SolidBody 1(CirPattern2) (L type-3),
SolidBody 1(CirPattern2) (L type-4),
SolidBody 1(CirPattern2) (Long U-1),
SolidBody 1(CirPattern2) (Long U-2),
SolidBody 1(CirPattern5) (One type-1),
SolidBody 1(CirPattern5) (One type-2),
SolidBody 1(CirPattern5) (One type-3),
SolidBody 1(CirPattern5) (One type-4),
SolidBody 1(CirPattern3) (Short U-1),
SolidBody 1(CirPattern3) (Short U-11),
SolidBody 1(CirPattern3) (Short U-12),
SolidBody 1(CirPattern3) (Short U-2),
SolidBody 1(CirPattern3) (Short U-3),
SolidBody 1(CirPattern3) (Short U-4),
SolidBody 1(CirPattern3) (Short U-5),
SolidBody 1(CirPattern3) (Short U-6),
SolidBody 1(CirPattern3) (Short U-7),
SolidBody 1(CirPattern3) (Short U-8),
SolidBody 1(CirPattern3) (Short U-9),
SolidBody 1(CirPattern6) (Waist-2),
SolidBody 1(Cut-Extrude1) (foot base-1),
SolidBody 1(Cut-Extrude1)
Design Analysis
65
(foot base-2),
SolidBody 1(CirPattern2) (oblique_U_bracket-1), SolidBody 1(CirPattern2) (oblique_U_bracket-2) Name: Nylon 6/10
Model type: Linear Elastic Isotropic Default
failure criterion:
Unknown
Yield strength:
1.39043e+00 8 N/m^2 Tensile
strength:
1.42559e+00 8 N/m^2 Elastic
modulus:
8.3e+009 N/m^2 Poisson's
ratio:
0.28 Mass
density:
1400 kg/m^3 Shear
modulus:
3.2e+009 N/m^2 Thermal
expansion coefficient:
3e-005 /Kelvin
SolidBody 1(Extrude11) (MG995-Servo_-1), SolidBody 1(Extrude11) (MG995-Servo_-2), SolidBody 1(Extrude11) (MG995-Servo_-3)
Design Analysis
66
Table 7-4: Fixture and Resultant Forces
Fixture
name Fixture Image Fixture Details
Fixed-1
Entities: 2 face(s)
Type: Fixed Geometry
Resultant Forces
Components X Y Z Resultant
Reaction force(N) 7.20131e-
007 6.37484 -7.08234e-
007 6.37484
Reaction
Moment(NΒ·m) 0 0 0 1e-033
Table 7-5: Load Details
Load name Image Load Details
Gravity-1
Top Plane
Reference: Top Values: 0 0 -9.81
Units: SI
Force-1
Entities: 2 face(s) Type: Apply normal
force Value: 0.2 N
Design Analysis
67
Table 7-6: Contact Information
Contact Contact Image Contact Properties
Contact Set-1
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-2
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-3
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-4
Type: Bonded contact pair Entities: 2 face(s)
Design Analysis
68
Contact Contact Image Contact Properties
Contact Set-5
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-6
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-7
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-8
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-9
Type: Bonded contact pair Entities: 2 face(s)
69
Contact Contact Image Contact Properties
Contact Set-10
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-11
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-12
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-13
Type: Bonded contact pair Entities: 2 face(s)
70
Contact Contact Image Contact Properties
Contact Set-14
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-15
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-16
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-17
Type: Bonded contact pair Entities: 2 face(s)
71
Contact Contact Image Contact Properties
Contact Set-18
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-19
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-20
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-21
Type: Bonded contact pair Entities: 3 face(s)
72
Contact Contact Image Contact Properties
Contact Set-22
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-23
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-24
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-25
Type: Bonded contact pair Entities: 2 face(s)
73
Contact Contact Image Contact Properties
Contact Set-26
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-27
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-28
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-29
Type: Bonded contact pair Entities: 2 face(s)
74
Contact Contact Image Contact Properties
Contact Set-30
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-31
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-32
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-33
Type: Bonded contact pair Entities: 2 face(s)
75
Contact Contact Image Contact Properties
Contact Set-34
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-35
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-36
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-37
Type: Bonded contact pair Entities: 2 face(s)
76
Contact Contact Image Contact Properties
Contact Set-38
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-39
Type: Bonded contact pair Entities: 2 face(s)
Contact Set-40
Type: Bonded contact pair Entities: 3 face(s)
Contact Set-41
Type: Bonded contact pair Entities: 2 face(s)
77
Contact Contact Image Contact Properties
Contact Set-42
Type: Bonded contact pair Entities: 2 face(s)
Global Contact
Type: Bonded Components: 1
componen t(s) Options: Compatibl
e mesh
Design Analysis
78
Table 7-7: Mesh Information
Mesh type Mixed Mesh
Mesher Used: Curvature based mesh
Jacobian points Off
Jacobian check for shell Off
Maximum element size 0 mm
Minimum element size 0 mm
Mesh Quality High
Remesh failed parts with incompatible mesh
Off
Table 7-8: Mesh Information β Details
Total Nodes 105789
Total Elements 51319
Maximum Aspect Ratio 106.77
% of elements with Aspect Ratio < 3 66.5
% of elements with Aspect Ratio > 10 5.36
% of distorted elements(Jacobian) 60.1
Design Analysis
79
Figure 7-3: Mesh Density Design Analysis
80
Table 7-9: Mesh Control Information
Mesh Control Name Mesh Control Image Mesh Control Details
Control-1
Entities: 43
component(s) Units: mm
Size: 1.50158 Ratio: 1.5
Resultant Forces
Table 7-10: Reaction Forces
Selection
set Units Sum X Sum Y Sum Z Resultant
Entire Model
N 7.20131e-
007
6.37484 -7.08234e- 007
6.37484
Table 7-11: Reaction Moments
Selection set
Units Sum X Sum Y Sum Z Resultant
Entire Model
NΒ·m 0 0 0 1e-033
Design Analysis
81 Study Results
Table 7-12: Stress Analysis (Von Mises)
Name Type Min Max
Stress VON: von Mises
Stress
1.02728 N/m^2 Node: 74527
1.71296e+007 N/m^2
Node: 3869
Figure 7-4: Static Stress (von Mises) Design Analysis
82
Table 7-13: Resultant Displacement
Name Type Min Max
Displacement URES: Resultant Displacement
0 mm
Node: 48022
1.98065 mm Node: 71820
Figure 7-5: Displacement Design Analysis
83
Table 7-14: Strain Analysis
Name Type Min Max
Strain ESTRN: Equivalent Strain
2.48225e-011 Element: 2876
0.000183533 Element: 1820
Figure 7-6: Strain Design Analysis
84
Table 7-15: Deformation Analysis
Name Type
Displacement1 Deformed Shape
Figure 7-7: Deformed Shape Design Analysis
85
7.3 Fatigue Analysis Analysis Condition:
Fixed geometry: Foot Base
External Force: 0.2 Newton Force Acting On L-Bracket Each Gravitational Force: 9.81 m/s2
Table 7-16: Fatigue Analysis Study
Study name Study 2
Analysis type Buckling
Mesh type Mixed 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
Table 7-17: Unit System
Unit system: SI (MKS)
Length/Displacement mm
Temperature Kelvin
Angular velocity Rad/sec
Pressure/Stress N/m^2
Design Analysis
86
Table 7-18: Fixture Details
Fixture
name Fixture Image Fixture Details
Fixed-1
Entities: 2 face(s) Type: Fixed
Geometry
Table 7-19: Load Details
Load
name Load Image Load Details
Force-1
Entities: 2 face(s) Type: Apply normal
force Value: 0.2 N
Gravity-1
Top plane
Reference: Top Values: 0 0 -9.81
Units: SI
Design Analysis
87
Table 7-20: Connector Detail
Pin Connector Connector Details
Entities: 2 face(s) Type: Pin
Connection type: With retaining ring (No translation) Rotational stiffness
value:
0
Units: SI
Table 7-21: Global Contact
Contact Contact Image Contact Properties
Global Contact
Type: Bonded Components: 1
component (s)
Options: Compatible mesh
Table 7-22: Mesh Detail
Mesh type Mixed Mesh
Mesher Used: Curvature based mesh
Jacobian points 4 Points
Jacobian check for shell On
Maximum element size 17.3184 mm Minimum element size 3.46368 mm
Mesh Quality High
Design Analysis
88 Remesh failed parts with
incompatible mesh
On
Table 7-23: Mesh Information β Details
Total Nodes 88812
Total Elements 42970
Figure 7-8: Mesh Density Design Analysis
89
Table 7-24: Displacement
Name Type Min Max
Displacement1 URES: Resultant Displacement Plot for Mode Shape: 1(Load Factor = -56.546)
0 mm
Node: 76572
30.5499 mm Node: 37426
Figure 7-9: Fatigue
Table 7-25:Mode List
Mode Number Load Factor
1 -56.546
Design Analysis
90
8
CONCLUSION AND
RECOMMENDATION
CHAPTER
91