Experimental, Analytical, and Numerical Studies on the Forward Extrusion Process

Fereshteh-Saniee, F.; Fakhar, N.; Karimi, Mehdi

doi:10.1080/10426914.2012.689454

Cited by 14 publications

(3 citation statements)

References 11 publications

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“…Some of the errors in the results can be attributed to insufficient device design data and testing data available for finite-element modeling, such as the specific device testing velocity, specific exact bulge profile data, bulge curvature radius, bulge angles, and bulge length. Previous studies suggested these parameters can potentially influence the extrusion forces outcomes (Lontos et al 2008;Fereshteh-Saniee et al 2013;Golondrino et al 2012a, b). The understrength of the experimental results in comparison with the FEM results can be explained by irregularity in prestress and can be achieved by further prestressing.…”

Section: Fem Force Prediction: Quantitative Validationmentioning

confidence: 97%

Nonlinear Finite-Element Modeling of HF2V Lead Extrusion Damping Devices: Generic Design Tool

2022

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Supplemental energy-dissipation devices are increasingly used to protect structures, limiting loads transferred to structures and absorbing significant response energy without sacrificial structural damage. The displacement of the bulged shaft plastically deforms lead in the high force to volume (HF2V) device, dissipating significant energy. HF2V devices are currently designed using limited precision models, so there is variability in force prediction. Further, although the outcome force is predicted, the knowledge of the exact internal mechanisms resulting in these device forces is lacking, limiting insight and predictive accuracy in device design. This study develops a generic finiteelement (FEM) model using commercially available software to better understand force generation and aid in precision device design, thus speeding up the overall design and implementation process for uptake and use. The model is applied to 17 experimental HF2V devices of various sizes. The highly nonlinear analysis is run using the software with automatic increments to balance higher accuracy and computational time. The total force output is sum of the friction forces between lead and steel and the contact pressure forces acting between moving shaft and displaced lead. FEM forces and plots of the 17 devices are compared with experimental device forces and test plots. The errors from force comparison for all 17 devices range from −8% (overprediction) to þ39% (underprediction) with a mean absolute error of 7.6% and a signed average error of 4.7%, indicating most errors were small. In particular, the standard error (SE) in manufacturing is SE ¼ AE14%. Overall, 13 of 17 devices (76%) are within AE1 SE of 14%; 3 of 17 devices (18%) are within AE2 SE (AE28%), and the last has −39% error, which is within AE3 SE ¼ AE42%. These results show low errors and a distribution of errors compared with experimental results that are within experimental device construction variability. The overall modeling methodology is objective and repeatable, and thus generalizable. The results validate the overall approach with relatively very low error, providing a general modeling methodology for accurate design of HF2V devices.

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Section: Fem Force Prediction: Quantitative Validationmentioning

confidence: 97%

Nonlinear Finite-Element Modeling of HF2V Lead Extrusion Damping Devices: Generic Design Tool

2022

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“…Therefore, Response Surface Methodology (RSM) aims at approximating the response function . In other words, RSM searches an optimal response in a sequence of designed experiments to find the relationship between dependent and independent variables 19 .…”

Section: Introductionmentioning

confidence: 99%

Finite-difference based response surface methodology to optimize tailgate support systems in longwall coal mining

Mahdevari

Hayati

2021

Sci Rep

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Designing a suitable support system is of great importance in longwall mining to ensure the safe and stable working conditions over the entire life of the mine. In high-speed mechanized longwall mining, the most vulnerable zones to failure are roof strata in the vicinity of the tailgate roadway and T-junctions. Severe roof displacements are occurred in the tailgate roadway due to the high-stress concentrations around the exposed roof span. In this respect, Response Surface Methodology (RSM) was utilized to optimize tailgate support systems in the Tabas longwall coal mine, northeast of Iran. The nine geomechanical parameters were obtained through the field and laboratory studies including density, uniaxial compressive strength, angle of internal friction, cohesion, shear strength, tensile strength, Young’s modulus, slake durability index, and rock mass rating. A design of experiment was developed through considering a Central Composite Design (CCD) on the independent variables. The 149 experiments are resulted based on the output of CCD, and were introduced to a software package of finite difference numerical method to calculate the maximum roof displacements (dmax) in each experiment as the response of design. Therefore, the geomechanical variables are merged and consolidated into a modified quadratic equation for prediction of the dmax. The proposed model was executed in four approaches of linear, two-factor interaction, quadratic, and cubic. The best squared correlation coefficient was obtained as 0.96. The prediction capability of the model was examined by testing on some unseen real data that were monitored at the mine. The proposed model appears to give a high goodness of fit with the accuracy of 0.90. These results indicate the accuracy and reliability of the developed model, which may be considered as a reliable tool for optimizing or redesigning the support systems in longwall tailgates. Analysis of variance (ANOVA) was performed to identify the key variables affecting the dmax, and to recognize their pairwise interaction effects. The key parameters influencing the dmax are respectively found to be slake durability index, Young’s modulus, uniaxial compressive strength, and rock mass rating.

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“…The outer race is one of critical load-carrying automobile parts that transmits moment of rotation between the transmission and a driven wheel. This outer race has six inner ball grooves, and is produced by a multi-stage warm forging process that includes forward extrusion [13,14], upsetting [15], first and second backward extrusions [10], necking, ironing, and sizing. In addition, to obtain the final product after finishing the multi-stage forging process, a machining process is also needed [11].…”

Section: Introductionmentioning

confidence: 99%

Process Simplification of Multi-Stage Forging for the Outer Race of a CV Joint

Kim²,

Kang

2014

Materials and Manufacturing Processes

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Constant velocity (CV) joint with six inner ball grooves has been conventionally produced by a multi-stage warm forging process that includes forward extrusion, upsetting, backward extrusions, necking, ironing, and sizing. In this study, multi-stage cold forging is presented with four simplified stages of forward extrusion, modified upsetting, backward extrusion, and combined necking-ironing-sizing. A three-dimensional numerical simulation is performed to ensure the appropriateness of the proposed process, and experimental investigations are carried out using spheroidized and phosphophyllite-coated SCr420H billet material. It is shown that the proposed multi-stage cold forging process could be successfully applied to the production of the outer race.

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Experimental, Analytical, and Numerical Studies on the Forward Extrusion Process

Cited by 14 publications

References 11 publications

Nonlinear Finite-Element Modeling of HF2V Lead Extrusion Damping Devices: Generic Design Tool

Nonlinear Finite-Element Modeling of HF2V Lead Extrusion Damping Devices: Generic Design Tool

Finite-difference based response surface methodology to optimize tailgate support systems in longwall coal mining

Process Simplification of Multi-Stage Forging for the Outer Race of a CV Joint

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