Transcript
OPTIMIZATION OF MACPHERSON SUSPENSION
SYSTEM
Under the guidance of
Prof. K. Muruganandham,
Kumaraguru college of technology
Submitted by,
Gautam Makeshbabu(0810103012)
Kumar.P (0810103023)
Objective
• Analyze the reasons for frequent failures in the TATA INDICA’s front wheel suspension system.
• To optimize the existing spring. To increase the stiffness and load carrying capacity of the spring.
• To decrease the shear stress acting on the spring.
Problem Analysis
Design Method
Usage Environment
Failure
Shape of spring
Coil diameter
Number of turns
Faulty manufacture
Unreasonable load
Poor maintenance
Rugged road conditions
Analysis of Existing spring
• The old spring is tested in Si’Tarc testing center and the stiffness value is found to be
• K=19.19 N/mm• Then the CATIA model is made, which is
imported in ANSYS and its analyzed for value of deflection and Stress.
• Using the formulae the value of deflection and stress values are found out.
CalculationStiffness calculation
K= 19.11 N/mm
Shear stress calculation:
C=10.08
k = 1.14
Shear stress T= 1103.84 N/mm2
Design of Experiments
• The parameter that can be changed are • Coil diameter• Shape of spring• Mean diameter and number of turns.
Factors High Low
Shape of Spring Helical Conical
Number of turns 7 6
Coil Diameter(mm) 12.7 12
• We have increased the coil diameter from 12 mm to 12.7 mm which is SWG 7/0.
• We also decreased the number of turns from 7 to 6.
• The spring is made conical and its maximum diameter of 160 mm and minimum diameter of 130 mm.
• The shear stress for the model is calculated and is checked with the maximum value.
Calculation
Comparison of resultsData Existing spring New spring
Spring type Helical Conical
Coil diamter 12 mm 12.7 mm
Mean diameter 131 mm -
Maximum dia and Minimum diameter 160 &130 mm
Number of turns 7 6
Stiffness 19.19 N/mm* 21.1 N/mm*
Maximum load carrying capacity 500 kgs* 584 kgs*
Maximum shear Stress 1103 N/mm2 1040 N/mm2
* - Data’s from Si’Tarc testing center.
Data
Results of existing spring
Deformation in ansys
Shear stress
Equivalent stress
Results for new spring
Deflection
Equivalent stress
Shear stress
Conclusion
• The optimized design is made by changing major parameters of existing spring.
• The new spring is manufactured and is tested in Si’Tarc lab.
• The stiffness is increased by 9.99% thereby the load carrying capacity is increased by 16%.
• The shear stress is decreased by 5.71%
Thank you
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