Browsing by Keyword "Finite elements"
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Item Adjustment of a High Pressure Die Casting Simulation Model against Experimental Data(2015-12-25) Anglada, Eva; Meléndez, Antton; Vicario, Iban; Arratibel, Ernesto; Aguillo, Idoia; CIRMETAL; Tecnalia Research & Innovation; PROMETALIn addition to the typical difficulties associated with the numerical simulation of metal casting processes, the special characteristics of the high pressure die casting (HPDC) increase the difficulty of obtaining reliable results. The process followed to define and adjust one HPDC simulation model against experimental measurements by means of inverse modelling, is presented together with information related with the test campaign. This knowledge may be of interest for other researchers interested in the HPDC simulation and/or in the simulation models adjustment. The case of study corresponds to the specific case of one variation of the alloy AlSi9Cu3 (in-house developed) and one variation of the H13 steel (in-house developed), used for the mold manufacturing. The simulation models include the mold thermal evolution during the consecutive cycles of the manufacturing process, together with the cavity filling and the later cooling of the alloy.Item Adjustment of Numerical Simulation Model to the Investment Casting Process(2013-09) Anglada, Eva; Meléndez, Antton; Maestro, Laura; Domínguez, Ignacio; Domiguez, I.; CIRMETAL; Tecnalia Research & InnovationThis paper presents the adjustment process of a simulation model to improve the correlation between simulation results and parts industrially manufactured. It includes the data registration at foundry plant, the preliminary set-up of the model and the later adjustment process to reach a correlation level according to the industrial necessities. The adjustment has been performed by means of inverse modelling. This technique uses thermal histories experimentally registered as base, and modifies the material properties and boundary conditions used in simulation until reaching a good correlation between numerical simulated cooling curves and they registered experimentally. The adjustment has been also focused on the shrinkage defects. The simulation model is a FEM model developed in commercial software specifically focused on metal casting simulation. The case of study is an investment casting process, vacuum poured, of a nickel base superalloy designated Hastelloy X. Usual in the manufacture of components for aeronautical turbines.Item Finite Element Model Correlation of an Investment Casting Process(Trans Tech Publications, 2014-06) Anglada, Eva; Meléndez, Antton; Maestro, Laura; Domínguez, Ignacio; CIRMETAL; Tecnalia Research & InnovationThe achievement of reliable simulations, in the case of complex processes as is the investment casting, is not a trivial task. Their accuracy is significantly related with the knowledge of the material properties and boundary conditions involved, but the estimation of these values usually is highly complex. One helpful option to try to avoid these difficulties is the use of inverse modelling techniques, where experimental temperature measurements are used as base to correlate the simulation models. The research presented hereafter corresponds to the correlation of a finite element model of the investment casting process of two nickel base superalloys, Hastelloy X and Inconel 718. The simulation model has been developed in a commercial software focused specifically on metal casting simulation. The experimental measurements used as base for the adjustment, have been performed at industrial facilities. The methodology employed combines the use of an automatic tool for model correlation with the manual adjustment guided by the researchers. Results obtained present a good agreement between simulation and experimental measurements, according to the industrial necessities. The model obtained is valid for the two studied cases with the only difference of the alloy material properties. The values obtained for the adjusted parameters in both cases are reasonable compared with bibliographic values. These two circumstances suggest that the obtained correlation is appropriate and no overfitting problems exist on it.Item Prediction and validation of shape distortions in the simulation of high pressure die casting(2018-06) Anglada, Eva; Meléndez, Antton; Vicario, Iban; Idoiaga, Jon Kepa; Mugarza, Aitz; Arratibel, Ernesto; CIRMETAL; Tecnalia Research & Innovation; PROMETALThe use of the thermomechanical simulation is very infrequent in the metal casting industry although the associated results are really useful for the manufacturing process. The main reasons are the complexity, the long calculation times and the difficulties to interpret the results. The parts manufactured by metal casting processes cool from its filling temperature to ambient, which causes a certain stress-strain state. Although the stress levels might be significant, the main worry of the foundrymen is usually the shape distortion. That is, the mismatches between the desired dimensions and the real ones. The problem is that the results obtained from numerical simulation are not directly useful to cover this industrial necessity. This work presents the prediction obtained using the thermomechanical simulation for the final dimensions of a component manufactured in aluminium alloy by high pressure die casting (HPDC) and its validation with the final dimensions of the manufactured component. The methodology established to forecast the mismatches with the reference geometry is also detailed, as it may be useful to encourage the use of this type of simulation in the metal casting industry.Item Rapid simulation models for aluminium furnaces design(2017-07-04) Anglada, Eva; Vicario, Iban; de Landia, Leonor; Mendizabal, Gorka; Toledo, Nagore; CIRMETAL; PROMETALThe minimisation of energy consumption in aluminium metal casting industries requires an appropriate design of the furnaces to reduce as possible the heat losses through the walls. Detailed simulation models have been developed that allow the in-depth study of furnace behaviour, but these models are too complex and slow for some industrial necessities. To make possible a fast evaluation during preliminary phases more agile models are needed. This agility may be achieved by simplified models, but the results could be affected by a lack of accuracy. The work presented hereafter shows how the steady state analysis of the furnace walls with simplified models of finite elements may give sufficiently accurate and fast results. The simulation models have been validated against experimental results, thus confirming their ability to adequately reproduce the thermal behaviour of the walls of several furnaces regardless of their composition or heating system.Item Simplified Models for High Pressure Die Casting Simulation(2015) Anglada, Eva; Meléndez, Antton; Vicario, Iban; Arratibel, Ernesto; Cangas, Gaizka; CIRMETAL; Tecnalia Research & Innovation; PROMETALThe simulation of the High Pressure Die Casting (HPDC) process is a complex type of simulation. The industrial procedure is based on consecutive manufacturing cycles that must be taken into account in the simulation. Moreover the part geometries use to be complex and the alloy is injected at really high velocities. All of that usually implies long calculation times that in complex cases can lead to several days. Sometimes, the circumstances require to have available a fast solution despite involve a loss of accuracy. The work presented hereafter discusses different possibilities to simplify the HPDC simulation models together with their benefits and drawbacks. The simplified simulation models have been validated against a detailed 3D simulation model, previously correlated with experimental results. The comparative, shows that the use of simplified models may be a solution that makes possible a big reduction in calculation times maintaining a reasonable level of accuracy.