PSI - Issue 79

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

66

the suspension system and the steering system of a car is the steering knuckle, which has neither a fixed geometry nor the same material in different cars [5, 6]. This component must withstand complex loading conditions throughout the vehicle’s operational life [7-9], making the integrity of its cast structure crucial to overall safety and performance. In other words, the geometry of the steering knuckle is inherently non-uniform and varies across vehicle platforms, which complicates mold filling, solidification behavior, and defect control during casting. Traditional trial-and-error approaches to mold design and process parameter selection often lead to suboptimal results, increased manufacturing costs, and longer development cycles. Consequently, the integration of casting simulation tools has become an essential part of modern casting design, enabling engineers to predict fluid flow, temperature gradients, solidification patterns, and potential defect zones prior to physical prototyping. The following are some of the important achievements of other researchers. Chen et al. have focused on the background and current status of numerical simulation of the casting process [10]. They reported that the progress in numerical simulation can be examined from different perspectives including casting solidification, casting filling, stress field, and microstructure. Thomas has provided a comprehensive report on the achievements as well as the remaining challenges in the simulation of continuous casting, considering interactive phenomena including heat transfer, solidification, multiphase turbulent flow, clogging, electromagnetic effects, complex interfacial behavior, stress, cracking, segregation, and microstructure formation [11]. Guo et al. have investigated the impact of melt properties on the quality of the casting process, as small changes in the composition of an alloy can significantly affect the thermophysical and physical properties of the molten and during solidification [12]. Dabade and Bhedasgaonkar have attempted to reduce the defect rate through analysis of variance based on Design of Experiment (DOE) and combining it with casting process simulation [13]. In this regard, they reported that by optimizing the sand parameters such as moisture content, compression strength, and permeability of molding and hardness, the defect rate of shrinkage porosity could be reduced by 15%. Khan and Sheikh have conducted a comparative study on different simulation software with the aim of metal casting process [14]. In this paper, they compared the process modeling in each software, their limitations and advantages. Finally, they reported which software could be a more suitable option, considering the purpose of the casting process simulation and the consideration of various parameters in it. In addition, casting design and proper design of the gating system have been studied to reduce casting defects such as shrinkage, porosity, and hot tears [15]. Fu and Yong have investigated the forecast of defects in casting products through simulation of pressure casting process [16]. Yang et al. have studied the defect characteristics of high-pressure die-cast aluminum alloy parts using various techniques including experimental and finite element calculations [17]. In this regard, the effect of local porosity and pore size on plasticity was also discussed. One of the advantages of the simulation performed in this paper compared to other papers is that it considers 3D solids with realistic defect distribution as input to build a finite element model, which was obtained using 3D X-ray computed tomography. Guan et al. have presented a mathematical model of heat transfer to simulate the change in shell temperature during the shell transfer process in precision casting [18]. In this model, a real-time dynamic correction method was used that uses thermocouple measurements to adjust for changes in ambient temperature, material diffusion coefficient, and thermal properties, which results in a more accurate simulation of the casting process than previous algorithms. As is clear from the above literature review, many articles have been presented in the field of casting process simulation and accurate finite element algorithms. In addition, many efforts have been made to optimize the casting process parameters with the aim of improving product quality and reducing casting defects. However, the industrial experiences of the first author as well as failure reports in various industries like automotive show that the use of other research achievements for parts with complex geometries or parts with new designs is not reliable and cannot completely eliminate casting defects. Therefore, there is a need for redesign and various analyses in the industry. Hence, this study uses advanced simulation techniques to analyze the sand casting process of a steering knuckle with complex geometry. Special emphasis is placed on determining the optimal position of the molten pool in the mold, a factor that significantly affects the thermal distribution and defect formation in the final product. By evaluating different pouring orientations and analyzing the associated thermal stresses and defect patterns – such as gas entrapment and shrinkage – this work aims to provide a robust framework for improving casting quality and ensuring the structural integrity of safety-critical automotive components.