Performance of leaf springs made of composite material subjected to low frequency impact loading

Abstract

This paper illustrates the possibility of replacing existing conventional steel-leaf spring by the leaf spring made by tailoring the layup of composite laminates. The dimensions of the existing conventional middle leaf (spring) of a commercial vehicle were chosen for the design and manufacture of die for moulding the composite leaves. Accordingly, suspension springs of composites of different layups with glass and carbon were fabricated and tested for flexure response. It is to be noted here that the cross sectional area of the composite leaf spring was the same as of the conventional leaf spring. By using universal testing machine, load per deflection and maximum load for each of the composite leaf springs were evaluated. Apart from these, the specimens were exposed to low frequency impact loading with specific duration of cycles and subsequently the flexure response was also evaluated. The low frequency impact on the composite leafs was effected with a laboratory loading set-up in a milling machine. Experimental results indicated the superior flexure response of the hybrid composites (with glass fiber at starting phase and carbon fiber at the end) and suggested possible alternative on comparison with the conventional spring.