Parabolic leaf springs are safety components on the suspension
system. They provide ride comfort due to calculated stiffness
characteristics and they absorb and release energy associated with
the road outputs of a fully loaded vehicle. Leaf springs determine
the desired vehicle ride height from the ground. As a critical
safety part, leaf spring endurance must be ensured.
Conventional leaf springs, multi-parabolic leaf springs and
parabolic leaf springs are the general types in use. The most
commonly used type of leaf spring is the parabolic leaf spring. The
main advantages of parabolic leaf springs are that they are
lighter, cheaper, with fatigue advantages, and they isolate more
noise.
Classical leaf spring design and prototype process methodology
consists of fatigue tests repeated for each case considering
different geometry alternatives, leaf layer additions, material and
suspension hard points improvements. This methodology takes a long
time and requires a significant budget.
In this study, five-layer parabolic leaf springs have been
optimized to four layers based on material, geometric design
improvement, nonlinear finite element analyze calculations
regarding boundary conditions of leaf spring. The rig test
validation of 5-layer parabolic leaf springs which is well
correlated with finite element results has been summarized. Later,
the finite element model of the new design has been generated by
decreasing weight through removing layers at the same boundary
conditions and evaluations have been made in comparison with the
first design.
Performance requirement considering load and deflection,
packaging requirements considering parabolic leaf spring length,
width, service requirement, risk assessments, business
considerations, and all other requirements regarding optimized
parabolic leaf spring design have been detailed.
This paper presents a precise method called the OlgunÇelik
virtual prototype process and will remain as a reference for leaf
spring producers and designers.