Reliability‐Based Casting Process Design Optimization

Abstract

Deterministic optimum designs are unreliable without consideration of the statistical and physical uncertainties in the casting process. In the present research, casting simulation is integrated with a general purpose reliability based design optimisation (RBDO) software tool that considers uncertainties in both the input variables as well as in the model itself. The output consists of an optimal design that meets a specified reliability. An example casting process design is presented where the shape of a riser is optimised while considering uncertainties in the fill level and riser diameter. It is shown that RBDO provides a much different optimum design than a traditional deterministic approach. The deterministic optimal solution offers a 12% increase in casting yield over typical safety margin design practice, but has an unacceptable 61% probability of failure. The RBDO design has a 7% increase in casting yield over the safety margin approach and a probability of failure of 4?6%.

Computer-Aided Engineering (CAE) Simulation for the Robust Gating System Design: Improved Process for Investment Casting Defects of 316L Stainless Steel Valve Housing

“…In the initial scheme, a closer casting pattern assembly method is used, and there is some shrinkage porosity found on the surface of the simulation result and trial casting. Minimizing the PSE closely related to the gating system is the casting gating system's eventual optimization goal [13,14]. The feeding system is a structure for storing the molten material to compensate for the possible shrinkage in the solidi cation phase during the casting process [15][16][17].…”

Computer-aided engineering (CAE) simulation for the robust gating system design: Improved process for investment casting defects of 316L stainless steel valve housing

“…In the initial scheme, a closer casting pattern assembly method is used, and there is some shrinkage porosity found on the surface of the simulation result and trial casting. Minimizing the PSE closely related to the gating system is the casting gating system's eventual optimization goal [13,14]. The feeding system is a structure for storing the molten material to compensate for the possible shrinkage in the solidi cation phase during the casting process [15][16][17].…”

Temperature Uncertainty Analysis of Injection Mechanism Based on Kriging Modeling

“…The former is irreducible, as in inherent variability, such as statistically distributed properties and manufacturing variability, while the latter is potentially reducible uncertainty due to lack of knowledge, such as model form and initial and boundary condition approximations. Recently, uncertainty modeling and optimization of the casting process has also attracted a considerable number of researchers (e.g., [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]). Tao et al [ 7 ] proposed a reliability-based multidisciplinary optimization model through finite element analysis of the die-casting process, in which the evidence theory is used to represent the epistemic uncertainty.…”

“…Tao et al [ 7 ] proposed a reliability-based multidisciplinary optimization model through finite element analysis of the die-casting process, in which the evidence theory is used to represent the epistemic uncertainty. Hardin et al [ 8 ] conducted casting simulation with a reliability based design optimization (RBDO) software that considers uncertainties in both the input variables as well as in modeling of itself. The riser design in the casting process example was optimized.…”