1. ME273 TEAM PROJECT
FEA Analysis of Steering Knuckle
ALIREZA MOUNESISOHI,
ANAM. A, AISHWARYA.G. S
2. INTRODUCTION
• Steering knuckle is one of the main components of
a car. This part is attached to other suspension
components, and contains the wheel hub. The main
functionality of this part is to withstand heavy
loading conditions while is allowing free rotation of
the front wheels.
• In this study, a 1200 kg Sedan’s steering knuckle is
investigated, and is optimized with using of Ansys
Finite Element Analysis package.
• Carbon Steel has been used as a material of the
steering knuckle. The selected material is one of the
most common materials in casting industry, due to
its high strength and low density.
Figure 1: Location of a knuckle in a car
3. PROBLEM STATEMENT
• A steering knuckle is been counting as the most of the weight of
all suspension components of a vehicle. If an overall weight of
suspension can be reduced, then the performance of the vehicle
can be improved. Consequently, it reduces fuel consumption,
and lessen CO2 emissions. Thus, steering knuckle can be
optimized in order to minimize its mass while maintaining the
allowable maximum Von-Mises Stress.
• This analysis study, considers forces on steering knuckle during
breaking condition, which is a very high stress case for the
subjected part.
Figure 2: components labeled which
attached to knuckle
Figure 3: Free Body Diagram of
wheel while is braking
4. DESIGN OBJECTIVES, CONSTRAINTS, AND VARIABLES
Design Objectives:
• Minimizing overall mass of the steering knuckle.
• Reducing the maximum total deformation of the design.
• Reducing the maximum Von-Misses stress of the model.
Design Constraint:
• Allowable Von Mises Stress is less than 257MPa.
• Total deformation is less than 1mm.
• Safety factor this heavy duty component is 4.
Design Variables:
• Thickness of tie rod mounting arm which is connected to steering shaft.
• Thickness of upper suspension mounting arm (vertical arm).
• Creating slots in the horizontal and vertical arm.
• Adding ribs to increase the stiffness of the part.
Figure 4:
P5 – thickness of tie rod arm
P6 – thickness of upper suspension arm
5. Meshing
Mesh Information
Nodes 21474
Method Automatic
Face Mesh Type Quad/ Tri
Elements 11664
Size Function Adaptive
Smoothing Medium
Element Size 10 mm
Element Mid Nodes Program Controlled
Shape Checking Standard Mechanical Figure 5: Meshed Modeled
6. BOUNDARY CONDITIONS
Boundary Conditions-Forces
Column1 Caused by Location Load Type Maginitude(N)
A Weight of the car Upper Suspension Mount Bearing Load 4500
B Weight of the car Upper Suspension Mount Bearing Load 4500
C Brake force Brake clipper
Bearing Load with
distatance(Moment)
2234.5
D Brake force Brake clipper
Bearing Load with
distatance(Moment)
2234.5
E Momentum (mass * speed) Upper Suspension Mount distributed force 9000
H steering movement Horizental Steering Mount Bearing Load 60
I Car Balance Balance Cliper and axis Bearing Load 10000
J Axial car load Axis Wheel Hub distributed force 1500
Boundary Conditions-Supports
Column1 Tied By Location Support Type Specification
F Ball bearing and Axes Connceted to the wheels' hub Cylindrical Suopport tan free, Rad fix, Axi fix
G Balanced Pin
Connected to the balanced
clipper
Cylindrical Suopport tan free, Rad fix, Axi fix
Table 1. Loads-Boundary Conditions
Table 2. Supports-boundary conditions
Figure 6. Fringe plot of Loads from ISO view
8. STATIC STRUCTURAL ANALYSES AFTER OPTIMIZATION
Figure 10: Stresses after optimizationFigure 9: Total deformation after optimization
9. STATIC ANALYSES AFTER FINAL OPTIMIZATION
Figure11: Optimized stresses after final optimization Figure 12: Optimized total deformation after final optimization
10. RESPONSE AND SENSITIVITY
Figure13. Response Plot of Deformation Vs P5 and P6 Figure 14. Sensitivity Chart for variables of P5 and P6
Figure 15. Response Plot of Geometry Mass Vs P5 and P6 Figure 16. Response Plot of Stress Vs P5 and P6
11. MASS OPTIMIZATION
Design parameter consideration:
As mass optimization results show that the thickness of tie-rod mounting arm can be reduced, we take it as our 1st design
parameter.
Observing max deformation and stress concentration areas, we choose upper suspension arm as 2nd design parameter.
12. CONCLUSIONS
• As it was mentioned in the problem statement, it’s tangible and efficient to reduce the total mass. After running the
Ansys simulation for the steering knuckle, the goal is been reached in all three targets:
• Weight of steering knuckle, which was our chief goal, was reduced by 15% after that the designed was optimized.
• It is been observed that the maximum Von Mises stress in the optimized design is lesser than the original design, while
the obtained maximum stress satisfies safety factor and yield stress for specific Carbon Steel.
• Maximum deformation of optimized model is also less the beginning model. It also satisfies the design constraints, to
be less than 1mm.
13. REFERENCES
1. P. Dumbre, A. K. Mishra, and V. S. Aher, “Structural Analysis of Steering Knuckle for Weight
Reduction,” International Journal of Emerging Technology and Advanced Engineering, Volume 4,
Issue 6, June 2014.
2. Website: http://repairpal.com/suspension-knuckle]"Suspension Knuckle", RepairPal.com, 2016.
3. B.Babu, M. Prabhu, P.Dharmaraj, and R.Sampath, “Stress analysis on steering knuckle of the
automobile,” International Journal of Research in Engineering and Technology.
4. M. P. Sharma, D. S. Mevawala, H. Joshi, and D. A. Patel,” Static Analysis of Steering Knuckle and Its
Shape Optimization,” IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE).
ACKNOWLEDGEMENT
• Thank you to ANSYS for providing us with licenses for FEA.
• Thank you to Dr. Chan for project support.
