PSI - Issue 79

Kazem Reza Kashyzadeh et al. / Procedia Structural Integrity 79 (2026) 65–72

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2. Methodology 2.1. Component Geometry and Material

The component selected for this simulation-based study, Figure 1, is a left-hand steering knuckle from a four cylindrical passenger vehicle with a 1500cc and 78hp power engine [19]. The geometry of the knuckle, illustrated in Figure 1, is characterized by its complex, multi-axial structure with significant variations in wall thickness. The primary functional areas include [20]:  Hub: cylindrical feature that houses the wheel bearing, with the thickest section to withstand high mechanical loads.  Arms: three slender arms that connect the hub to the suspension strut, tie rod, and lower control arm. These arms are subject to high bending and torsional stresses.  Junctions and Transition Zones: critical areas where the arms meet the hub and each other, featuring complex geometries and potential stress concentration points.

Fig. 1. Geometry of the steering knuckle considered in this study.

This combination of thin sections and thick junctions creates challenging thermal dynamics during solidification, making the knuckle highly susceptible to defects like shrinkage porosity in the hub and thermal stress-induced hot tearing at the arm junctions. The material specified for the casting is ductile cast Iron grade EN-GJS-700-2. The following material properties, central to the accuracy of the simulation, were defined within the software's database: Liquidus and solidus temperature are 1150 °C and 1135 °C, respectively. Density in solid state was considered 7100 kg/m³ and a bit lower for liquid state. Moreover, thermal conductivity and specific heat capacity are defined as