Enhancement of fatigue life of multi-leaf spring by parameter optimization using RSM

  • Vinkel Kumar AroraEmail author
  • Gian Bhushan
  • M. L. Aggarwal
Technical Paper


The experimental investigation to predict the effect of mechanical processing, strength reduction factors, design, geometric tolerances and material factors on the fatigue life of a leaf spring is costly and time-consuming process. A computer program based on the analytical approach has been developed in FORTRAN, for determination of the fatigue life of a leaf spring of a light commercial vehicle. It takes into account the effect of five factors namely overall strength reduction factor (processing), stiffness (design), span and width (geometry) and ultimate tensile strength (material) on the fatigue life of the leaf spring. The results of the program have been validated experimentally using a full-scale leaf spring testing machine. A mathematical model has also been developed using response surface methodology. The optimal sets of parameters yielding the maximum fatigue life are obtained using the desirability approach. The confirmatory experiments are carried out and the results indicate that the developed model is appropriate for determination of fatigue life within 5 % variation. The interaction effects of the factors affecting fatigue life have also been studied and the overall strength reduction factor is found to be the most significant one.


Leaf spring Fatigue life Design factor Geometry factor Strength reduction factor Material factor 



No load assembly camber


Young’s modulus of elasticity


No. of cycles to failure


Predicted fatigue life




Poisson’s ratio


Alternating stress


Maximum stress


Endurance limit


Corrected endurance limit


Yield tensile strength




Minimum stress


Mean Stress


Equivalent alternating stress


Ultimate tensile strength


Surface factor


Load factor


Temperature factor


Size factor


Reliability factor


Stress at 103 cycles



The authors would like to acknowledge Mr. P S Chawla and the leaf springs testing division of Friends Auto (India) Ltd, whose unconditional support have made this project successful.


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Copyright information

© The Brazilian Society of Mechanical Sciences and Engineering 2016

Authors and Affiliations

  • Vinkel Kumar Arora
    • 1
    Email author
  • Gian Bhushan
    • 2
  • M. L. Aggarwal
    • 3
  1. 1.Department of EngineeringNIFTEM, HSIIDCKundliIndia
  2. 2.Department of Mechanical EngineeringNational Institute of TechnologyKurukshetraIndia
  3. 3.Department of Mechanical EngineeringYMCA University of Science and TechnologyFaridabadIndia

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