A multi-objective optimization method for the composite leaf spring of a type of buses is described to optimize the performance of the composite leaf spring. A multi-objective optimization model is established in the genetic algorithm toolbox of Matlab software by using the weighting coefficient transformation method and the hybrid method in genetic algorithms. The variables of the model are parameters of the layer scheme and the stiffness
the strength ratio and the mass of the composite leaf spring are sub-goals of the model. A Matlab program is coded to calculate the performance of the composite leaf spring. The results show that the width of the composite leaf spring should be maximized and the thickness of the composite leaf spring parabolically increases from the end of the layer region with gradient length towards the bump structure. The prototypes of the optimal design scheme are manufactured and a bench test is performed. The test results show that the mass and the fatigue life of the composite leaf spring are 40% and three times of those of the steel leaf spring
respectively. Moreover
the stiffness and the strength of the composite leaf spring also meet the requirements of this type of buses.
WU Hui, LI Zaike, JIANG Qibin. Development and characteristics of composite's leaf spring [J]. China Plastics Industry, 2012, 40(8): 103-106.
SUBRAMANIAN C, SENTHILVELAN S. Short-term flexural creep behavior and model analysis of a glass-fiber-reinforced thermoplastic composite leaf spring [J]. Journal of Applied Polymer Science, 2011, 120(6): 3679-3686.
RAJENDRAN I, VIJAYARANGAN S. Design, analysis, fabrication and testing of a composite leaf spring [J]. Mechanical Engineering Division, 2002, 82(3): 180-187.
SHOKRIEH M M, REZAEI D. Analysis and optimization of a composite leaf spring [J]. Composite Structures, 2003, 60(3): 317-325.
RAJENDRAN I, VIJAYARANGAN S. Optimal design of a composite leaf spring using genetic algorithms [J]. Computers Structures, 2001, 79(11): 1121-1129.
KUMAR M S, VIJAYARANGAN S. Analytical and experimental studies on fatigue life prediction of steel and composites multi-leaf spring for light passenger vehicles using life data analysis [J]. Materials Science, 2007, 13(2): 141-146.
SUBRAMANIAN C, SENTHILVELAN S. Joint performance of the glass fiber reinforced polypropylene leaf spring [J]. Composite Structures, 2011, 93(2): 759-766.
王耀先. 复合材料力学与结构设计 [M]. 上海: 华东理工大学出版社, 2012: 50-67.
FERREIRA J A M, COSTA J D M, REIS P N B. Static and fatigue behavior of glass-fibre-reinforced polypropylene composites [J]. Theoretical and Applied Fracture Mechanics, 1999, 31(1): 67-74.
KUEH J J, FARIS T. Finite element analysis on the static and fatigue characteristics of composite multi-leaf spring [J]. Journal of Zhejiang University: A Science, 2012, 13(3): 159-164.