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Taylan Altan

Bio: Taylan Altan is an academic researcher from Ohio State University. The author has contributed to research in topics: Forging & Finite element method. The author has an hindex of 59, co-authored 270 publications receiving 14494 citations. Previous affiliations of Taylan Altan include University College of Engineering & DuPont.


Papers
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4 citations

Journal ArticleDOI
TL;DR: In this article, a simple load calculation method and its application to forging a steel connecting rod are described and compared with the results of computer-aided analysis and with experimental forging data.
Abstract: The forging engineer must often estimate the load necessary in a press forging operation. Thus, the appropriate press capacity can be selected and, in some cases, it can be decided whether or not in-house capability exists for quoting on a given forging. This paper describes a simple load calculation method and its application to forging a steel connecting rod. The results, obtained with a hand calculator, are evaluated by comparing them with the results of computer-aided analysis and with experimental forging data. This comparison indicated that hand calculator results are sufficiently accurate for estimating forging loads and stresses. It is expected that the technique, described in this paper, will be a useful tool for the engineers in forge shop practice.

3 citations

Proceedings ArticleDOI
09 Jul 2004
TL;DR: In this article, the authors used numerical optimization, adaptive simulation and finite element analysis of the stamping process to predict constant and variable binder force (variation in stroke) to form the part without failure and with reduced springback.
Abstract: Introduction of multiple point cushion technology in stamping press has provided an additional degree of freedom to improve the formability of the materials by changing the blank holder/binder/cushion force in space/location and in stroke during the process. However, this advanced capacity of die cushion is being underutilized in production because it is difficult to estimate the force required in each pin and its variation throughout the press stroke to form a part with desired quality. This paper describes two methods namely, a) Numerical Optimization, b) Adaptive simulation coupled with finite element analysis of the stamping process to predict constant and variable binder force (variation in stroke) to form the part without failure and with reduced springback. The blank holder force is predicted by detection of a) wrinkles, b) thinning and c) stress variation through thickness direction during the FE simulation to eliminate potential defects such as wrinkles and thinning and reduce springback in the part. The developed technique was applied to two parts namely a) IFU Hishida die, and b) Numisheet S‐Rail to predict blank holder force to minimize thinning and springback respectively.

3 citations

Journal ArticleDOI
TL;DR: Diaz-Infante et al. as discussed by the authors determined the effect of selected AWJ cutting parameters on the hole expansion ratio (HER) for a DP800 (Dual-Phase) Advanced High-Strength Steel (AHSS) with s 0 = 1.2 mm by using a fractional factorial design of experiments for the Hole Expansion Tests (HET).
Abstract: The use of Abrasive Water Jet (AWJ) cutting technology can improve the edge stretchability in sheet metal forming. The advances in technology have allowed significant increases in working speeds and pressures, reducing the AWJ operation cost. The main objective of this work was to determine the effect of selected AWJ cutting parameters on the Hole Expansion Ratio (HER) for a DP800 (Dual-Phase) Advanced High-Strength Steel (AHSS) with s0 = 1.2 mm by using a fractional factorial design of experiments for the Hole Expansion Tests (HET). Additionally, the surface roughness and residual stresses were measured on the holes looking for a possible relation between them and the measured HER. A deep drawing quality steel DC06 with s0 = 1.0 mm was used for reference. The fracture occurrence was captured by high-speed cameras and by Acoustic Emissions (AE) in order to compare both methods. Results indicated that using, regardless of the material, a small standoff distance, high water pressure, and slow traverse speed and cutting the sample underwater will delay the fracture in a hole expansion operation. Furthermore, the AE have proven to be adequate to measure cracks when optical methods are not feasible. In conclusion, based on the impact of the aforementioned parameters, it is possible to select, appropriately, the AWJ operation parameters to achieve the edge stretchability required for each forming process. Downloaded from SAE International by David Diaz-Infante, Tuesday, October 02, 2018

3 citations


Cited by
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TL;DR: In this paper, a Lagrangian finite element method of fracture and fragmentation in brittle materials is developed, where a cohesive-law fracture model is used to propagate multiple cracks along arbitrary paths.

1,970 citations

Journal ArticleDOI
TL;DR: Electrical discharge machining (EDM) has been continuously evolving from a mere tool and die making process to a micro-scale application machining alternative attracting a significant amount of research interests as mentioned in this paper.
Abstract: Electrical discharge machining (EDM) is a well-established machining option for manufacturing geometrically complex or hard material parts that are extremely difficult-to-machine by conventional machining processes. The non-contact machining technique has been continuously evolving from a mere tool and die making process to a micro-scale application machining alternative attracting a significant amount of research interests. In recent years, EDM researchers have explored a number of ways to improve the sparking efficiency including some unique experimental concepts that depart from the EDM traditional sparking phenomenon. Despite a range of different approaches, this new research shares the same objectives of achieving more efficient metal removal coupled with a reduction in tool wear and improved surface quality. This paper reviews the research work carried out from the inception to the development of die-sinking EDM within the past decade. It reports on the EDM research relating to improving performance measures, optimising the process variables, monitoring and control the sparking process, simplifying the electrode design and manufacture. A range of EDM applications are highlighted together with the development of hybrid machining processes. The final part of the paper discusses these developments and outlines the trends for future EDM research.

1,421 citations

Book
09 Mar 1989
TL;DR: In this paper, the finite element method was used to analyze the metal forming process and its properties, including plasticity, viscoplasticity, and plane-strain problems.
Abstract: Introduction Metal forming process Analysis and technology in metal forming Plasticity and viscoplasticity Methods of analysis The finite element method (1) The finite element method (2) Plane-strain problems Axisymmetric isothermal forging Steady state processes of extrusion and drawing Sheet metal forming Thermo-viscoplastic analysis Compaction and forging of porous metals Three dimensional problems Preform design in metal forming Solid formulation, comparison of two formulations, and concluding remarks Index.

1,226 citations

Journal ArticleDOI
TL;DR: In this article, the boundary layer flow induced in a nanofluid due to a linearly stretching sheet is studied numerically and the transport equations include the effects of Brownian motion and thermophoresis.

1,086 citations

Journal ArticleDOI
TL;DR: In this paper, the authors give an account of the development of the idea of yield stress for solids, soft solids and structured liquids from the beginning of this century to the present time.
Abstract: An account is given of the development of the idea of a yield stress for solids, soft solids and structured liquids from the beginning of this century to the present time. Originally, it was accepted that the yield stress of a solid was essentially the point at which, when the applied stress was increased, the deforming solid first began to show liquid-like behaviour, i.e. continual deformation. In the same way, the yield stress of a structured liquid was originally seen as the point at which, when decreasing the applied stress, solid-like behaviour was first noticed, i.e. no continual deformation. However as time went on, and experimental capabilities increased, it became clear, first for solids and lately for soft solids and structured liquids, that although there is usually a small range of stress over which the mechanical properties change dramatically (an apparent yield stress), these materials nevertheless show slow but continual steady deformation when stressed for a long time below this level, having shown an initial linear elastic response to the applied stress. At the lowest stresses, this creep behaviour for solids, soft solids and structured liquids can be described by a Newtonian-plateau viscosity. As the stress is increased the flow behaviour usually changes into a power-law dependence of steady-state shear rate on shear stress. For structured liquids and soft solids, this behaviour generally gives way to Newtonian behaviour at the highest stresses. For structured liquids this transition from very high (creep) viscosity (>106 Pa.s) to mobile liquid (

950 citations