DESIGN AGAINST FATIGUE LOAD PDF

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DESIGN AGAINST FATIGUE LOAD Questions and Ansys Simulation...

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ASSIGNMENT -02, DESIGN AGAINST FATIGUE LOAD Q 1. A plate made of steel 20C8 in hot rolled and normalized condition is shown in fig.1 It is subjected to a completely reversed load of P.The notch sensitivity factor q can be taken as 0.8 and the expected reliability is 90 %.( k0.897).F.S=2. The size factor can be taken as 0.85.determine the plate thickness for infinite life. Take surface finish factor 0.67. Take P =30kN, 25KN, 35 KN, 20 KN, 40KN, 45KN. Q.2. A rod of linkage mechanism made of steel 45 C 8 is subjected to a completely reversed axial load of P. The rod is machined on lathe and the expected reliability is 95%.there is no stressconcentration.Determine the diameter of the rod using a factor of safety of 2. For an infinite life condition. Take Kc=0.868, Ka=0.78,Kb=0.85 P=100KN,90KN,80KN,120KN,70KN,60KN. (Ka: Surface finish factor, Kb: Size factor, Kc: Reliability factor ) Q.3. A rotating bar made of steel 45 C8 is subjected to a completely reversed bending stress. The corrected endurance limit of the bar is 315N/mm2 .Calculate the fatigue strength of the bar for a life of 90000 cycles. For a finite life condition. Q.4.A cantilever beam made of cold drawn steel 20C8 is subjected to a completely reversed load of P.as shown in fig. 2.The notch sensitivity factor q at the fillet can be taken as 0.85 and expected reliability is 90 %.( kc=0.897) Determine the diameter d of the beam for a life of 10000 cycles. P=100KN, 90KN, 80KN, 120KN, 70KN, 60KN , Take Kb=0.85, Ka=0.78., Kc=1.35

Fig -2

Q 5.The work cycle of a mechanical component subjected to completely reversed bending stresses consists of the following three elements: i) ± 360N/mm2 for 85% of time ii) ± 400N/mm2 for 12% of time iii) ± 520 N/mm2 for 3% of time The material for the component is 55C8 and the corrected endurance limit of the component is 260N/mm2.Determine the life of the component.

Q.6.A part made of 50C8 steel is subjected to reversed bending loading where 15% of its life is spent at an stress level 300Mpa,30% is spent at a stress level of 325MPa and the remaining at a stess level of 376MPa.Determine the total number of cycles that the part can endure before final failure. Take Ksur=0.797 Ksize=0.87 and Reliability factor is 0.897.

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Project* First Saved Thursday, January 14, 2021 Last Saved Thursday, January 14, 2021 Product Version 2020 R2 Save Project Before Solution No Save Project After Solution No

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Contents l

Units

l

Model (A4) ¡ Geometry n Part n ¡ ¡

¡ ¡ ¡ ¡

l

Parts

Materials Cross Sections n Rect1 Coordinate Systems Connections Mesh Static Structural (A5) n Analysis Settings n Loads n Solution (A6) n Solution Information n Results

Material Data ¡ Concrete

Units TABLE 1 Unit System Metric (mm, kg, N, s, mV, mA) Degrees rad/s Celsius Angle Degrees Rotational Velocity rad/s Temperature Celsius

Model (A4) Geometry

Object Name State Source Type Length Unit Element Control Display Style Length X Length Y

TABLE 2 Model (A4) > Geometry Geometry Fully Defined Definition C:\Users\KIIT\Desktop\Labs\6th Semester\CADA Lab\Exp-2\Exp-2_files\dp0 \SYS\DM\SYS.agdb DesignModeler Meters Program Controlled Body Color Bounding Box 4500. mm 0. mm

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Length Z

0. mm Properties

Volume Mass Scale Factor Value

7.9601e+007 mm³ 183.08 kg 1. Statistics

Bodies Active Bodies Nodes Elements Mesh Metric

3 3 43 21 None Update Options

Assign Default Material Parameters Parameter Key Attributes Attribute Key Named Selections Named Selection Key Material Properties Use Associativity Coordinate Systems Coordinate System Key Reader Mode Saves Updated File Use Instances Smart CAD Update Compare Parts On Update Analysis Type Clean Bodies On Import Stitch Surfaces On Import Decompose Disjoint Geometry Enclosure and Symmetry Processing

No Basic Geometry Options Independent Yes Yes Yes Advanced Geometry Options Yes Yes No Yes Yes No 3-D No None Yes Yes TABLE 3 Model (A4) > Geometry > Body Groups Part Object Name State Meshed Graphics Properties Visible Yes Definition Suppressed No Assignment Concrete Coordinate System Default Coordinate System Bounding Box Length X 4500. mm Length Y 0. mm Length Z 0. mm Properties Volume 7.9601e+007 mm³

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Mass 183.08 kg Statistics Nodes 43 Elements 21 Mesh Metric None TABLE 4 Model (A4) > Geometry > Part > Parts Object Name Line Body Line Body Line Body State Meshed Graphics Properties Visible Yes Transparency 1 Definition Suppressed No Stiffness Behavior Flexible Coordinate System Default Coordinate System Reference Temperature By Environment Cross Section Rect1 Offset Mode Refresh on Update Offset Type Centroid Treatment None Model Type Beam Material Assignment Concrete Nonlinear Effects Yes Thermal Strain Effects Yes Bounding Box Length X 1500. mm Length Y 0. mm Length Z 0. mm Properties Volume 2.6534e+007 mm³ Mass 61.027 kg Length 1500. mm Cross Section Area 17689 mm² Cross Section IYY 2.6075e+007 mm²·mm² Cross Section IZZ 2.6075e+007 mm²·mm² Statistics Nodes 15 Elements 7 Mesh Metric None TABLE 5 Model (A4) > Materials Object Name Materials State Fully Defined Statistics Materials 2 Material Assignments 0 TABLE 6 Model (A4) > Cross Sections

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Object Name Cross Sections State Fully Defined Statistics Cross Sections 3

Object Name State Type Import Type B H Beam Section A Iyy Izz

TABLE 7 Model (A4) > Cross Sections > Rect1 Rect1 Rect2 Rect3 Fully Defined Definition RECT Imported Dimensions 133. mm 200. mm 300. mm 133. mm 200. mm 300. mm Physical Properties Rect1 Rect2 Rect3 17689 mm² 40000 mm² 90000 mm² 2.6075e+007 mm²·mm² 1.3333e+008 mm²·mm² 6.75e+008 mm²·mm² 2.6075e+007 mm²·mm² 1.3333e+008 mm²·mm² 6.75e+008 mm²·mm²

Coordinate Systems TABLE 8 Model (A4) > Coordinate Systems > Coordinate System Object Name Global Coordinate System State Fully Defined Definition Type Cartesian Coordinate System ID 0. Origin Origin X 0. mm Origin Y 0. mm Origin Z 0. mm Directional Vectors X Axis Data [ 1. 0. 0. ] Y Axis Data [ 0. 1. 0. ] Z Axis Data [ 0. 0. 1. ]

Connections TABLE 9 Model (A4) > Connections Object Name Connections State Fully Defined Auto Detection Generate Automatic Connection On Refresh Yes Transparency Enabled Yes

Mesh

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TABLE 10 Model (A4) > Mesh Mesh Object Name State Solved Display Display Style Use Geometry Setting Defaults Physics Preference Mechanical Element Order Program Controlled Element Size Default Sizing Use Adaptive Sizing Yes Resolution Default (2) Mesh Defeaturing Yes Defeature Size Default Transition Fast Span Angle Center Coarse Initial Size Seed Assembly Bounding Box Diagonal 4500.0 mm Average Surface Area 0.0 mm² Minimum Edge Length 1500.0 mm Quality Check Mesh Quality Yes, Errors Error Limits Aggressive Mechanical Target Quality Default (0.050000) Smoothing Medium Mesh Metric None Inflation Use Automatic Inflation None Inflation Option Smooth Transition Transition Ratio 0.272 Maximum Layers 5 Growth Rate 1.2 Inflation Algorithm Pre View Advanced Options No Batch Connections Mesh Based Connection No Advanced Number of CPUs for Parallel Part Meshing Program Controlled Straight Sided Elements No Rigid Body Behavior Dimensionally Reduced Triangle Surface Mesher Program Controlled Topology Checking Yes Pinch Tolerance Please Define Generate Pinch on Refresh No Statistics Nodes 43 Elements 21

Static Structural (A5) TABLE 11

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Model (A4) > Analysis Object Name Static Structural (A5) State Solved Definition Physics Type Structural Analysis Type Static Structural Solver Target Mechanical APDL Options Environment Temperature 22. °C Generate Input Only No TABLE 12 Model (A4) > Static Structural (A5) > Analysis Settings Analysis Settings Object Name State Fully Defined Step Controls Number Of Steps 1. Current Step Number 1. Step End Time 1. s Auto Time Stepping Program Controlled Solver Controls Solver Type Program Controlled Weak Springs Off Solver Pivot Checking Program Controlled Large Deflection Off Inertia Relief Off Quasi-Static Solution Off Rotordynamics Controls Coriolis Effect Off Restart Controls Generate Restart Points Program Controlled Retain Files After Full Solve No Combine Restart Files Program Controlled Nonlinear Controls Newton-Raphson Option Program Controlled Force Convergence Program Controlled Moment Convergence Program Controlled Displacement Convergence Program Controlled Rotation Convergence Program Controlled Line Search Program Controlled Stabilization Program Controlled Advanced Inverse Option No Contact Split (DMP) Off Output Controls Stress Yes Surface Stress No Back Stress No Strain Yes Contact Data Yes Nonlinear Data No Nodal Forces No Volume and Energy Yes

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Euler Angles General Miscellaneous Contact Miscellaneous Store Results At Result File Compression Solver Files Directory Future Analysis Scratch Solver Files Directory Save MAPDL db Contact Summary Delete Unneeded Files Nonlinear Solution Solver Units Solver Unit System

Object Name State Scoping Method Geometry Type Suppressed Define By Coordinate System X Component Y Component Z Component Applied By

Yes No No All Time Points Program Controlled Analysis Data Management C:\Users\KIIT\Desktop\Labs\6th Semester\CADA Lab\Exp-2\Exp-2_files\dp0 \SYS\MECH\ None

No Program Controlled Yes No Active System nmm

TABLE 13 Model (A4) > Static Structural (A5) > Loads Fixed Support Displacement Force Force 2 Fully Defined Scope Geometry Selection 1 Vertex 1 Edge Definition Fixed Support Displacement Force No Components

Force 3

1 Vertex

Global Coordinate System Free 0. mm (ramped) 0. mm (ramped)

-12000 N (ramped)

0. N (ramped) -10000 N (ramped) 0. N (ramped)

Surface Effect FIGURE 1 Model (A4) > Static Structural (A5) > Displacement

-20000 N (ramped)

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FIGURE 2 Model (A4) > Static Structural (A5) > Force

FIGURE 3 Model (A4) > Static Structural (A5) > Force 2

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FIGURE 4 Model (A4) > Static Structural (A5) > Force 3

Solution (A6)

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TABLE 14 Model (A4) > Static Structural (A5) > Solution Object Name Solution (A6) State Solved Adaptive Mesh Refinement Max Refinement Loops 1. Refinement Depth 2. Information Status Done MAPDL Elapsed Time 3. s MAPDL Memory Used 86. MB MAPDL Result File Size 384. KB Post Processing Beam Section Results No On Demand Stress/Strain No TABLE 15 Model (A4) > Static Structural (A5) > Solution (A6) > Solution Information Object Name Solution Information State Solved Solution Information Solution Output Solver Output Newton-Raphson Residuals 0 Identify Element Violations 0 Update Interval 2.5 s Display Points All FE Connection Visibility Activate Visibility Yes Display All FE Connectors Draw Connections Attached To All Nodes Line Color Connection Type Visible on Results No Line Thickness Single Display Type Lines TABLE 16 Model (A4) > Static Structural (A5) > Solution (A6) > Results Object Name Total Deformation Total Bending Moment Total Shear Force State Solved Scope Scoping Method Geometry Selection Geometry All Bodies All Line Bodies Definition Type Total Deformation Total Bending Moment Total Shear Force By Time Display Time Last Calculate Time History Yes Identifier Suppressed No Results Minimum 0. mm 1.1984e-007 N·mm 7527.6 N Maximum 31.865 mm 2.7874e+007 N·mm 28670 N Average 17.482 mm

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Minimum Occurs On Maximum Occurs On

Line Body Line Body Information

Time Load Step Substep Iteration Number Display Option

1. s 1 1 1 Integration Point Results Unaveraged

FIGURE 5 Model (A4) > Static Structural (A5) > Solution (A6) > Total Deformation

TABLE 17 Model (A4) > Static Structural (A5) > Solution (A6) > Total Deformation Time [s] Minimum [mm] Maximum [mm] Average [mm] 1. 0. 31.865 17.482 FIGURE 6 Model (A4) > Static Structural (A5) > Solution (A6) > Total Deformation > Figure

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FIGURE 7 Model (A4) > Static Structural (A5) > Solution (A6) > Total Bending Moment

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TABLE 18 Model (A4) > Static Structural (A5) > Solution (A6) > Total Bending Moment Time [s] Minimum [N·mm] Maximum [N·mm] 1. 1.1984e-007 2.7874e+007 FIGURE 8 Model (A4) > Static Structural (A5) > Solution (A6) > Total Bending Moment > Figure

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FIGURE 9 Model (A4) > Static Structural (A5) > Solution (A6) > Total Shear Force

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TABLE 19 Model (A4) > Static Structural (A5) > Solution (A6) > Total Shear Force Time [s] Minimum [N] Maximum [N] 1. 7527.6 28670 FIGURE 10 Model (A4) > Static Structural (A5) > Solution (A6) > Total Shear Force > Figure

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Material Data Concrete TABLE 20 Concrete > Constants Density 2.3e-006 kg mm^-3 Coefficient of Thermal Expansion 1.4e-005 C^-1 Specific Heat 7.8e+005 mJ kg^-1 C^-1 Thermal Conductivity 7.2e-004 W mm^-1 C^-1 TABLE 21 Concrete > Color Red Green Blue 180 173 167 TABLE 22 Concrete > Compressive Ultimate Strength Compressive Ultimate Strength MPa 41 TABLE 23

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Concrete > Compressive Yield Strength Compressive Yield Strength MPa 0 TABLE 24 Concrete > Tensile Yield Strength Tensile Yield Strength MPa 0 TABLE 25 Concrete > Tensile Ultimate Strength Tensile Ultimate Strength MPa 5 TABLE 26 Concrete > Isotropic Secant Coefficient of Thermal Expansion Zero-Thermal-Strain Reference Temperature C 22 TABLE 27 Concrete > Isotropic Elasticity Young's Modulus MPa Poisson's Ratio Bulk Modulus MPa Shear Modulus MPa Temperature C 30000 0.18 15625 12712...