Tie rod is one of the critical components in automotive steering mechanism, which provides
mechanical connection between knuckle and steering rack. It is subjected to time varying and static
loads during its service life, leading to failures like fatigue and buckling. Therefore, determination of
optimum design that can compensate these loads is an important aspect for vehicle weight in product
development cycle. One of the main concerns is buckling behavior of Tie-rod, which is mostly
determined by Outer Tie Rod shape. Due to the movement of other chassis components (e.g. control
arm, wheel) in vehicle kinematic, Outer Tie Rods are designed in a limited space. Furthermore, it is
requested to have enough mechanical strength in order to transmit steering gear force to the wheels
properly. In consideration of these restrictions, it is always desired Outer Tie Rod to have an optimum
design in terms of weight and strength. In this study, design and weight optimization of Outer Tie Rod
made of micro-alloyed steel is conducted. First, the pre-determined design is created according to
vehicle requirements. In order to find an optimum design, the cross-section dimensions affecting
buckling behavior are defined as design parameters and then, Finite Element analysis is conducted
based on GRSM (Global Response Search Method) optimization approach by using HyperStudy.
Several analyses by optimizing the cross section of Outer Tie-Rod are solved to obtain the intended
value of buckling force. First and optimized designs are compared in terms of weight and buckling
behavior. Consequently, a lightweight Outer Tie rod design that can also fulfill the buckling
requirement is proposed.
Anahtar Kelimeler: Tie rod, buckling behavior, lightweight, non-linear optimization, FEA
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