Assessment and improvement of elementary force computations for cold forward rod extrusion

Date

2005-06-01

Author

Ocal, M
Egemen, N
Tekkaya, AE

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

210
views

0
downloads

Two commonly used analytical force computation methods for cold forward rod extrusion are evaluated by means of precise finite element computations. The upperbound model by Avitzur based on the spherical velocity field and the model by Siebel based on a quasi-upper-bound solution are considered. It has been found that the pure deformation forces obtained by summing the ideal force and shear force terms deviate between +25% and -20% from the finite element solutions. Larger deviations, however, occur for the Coulomb-friction term in the container. A new model based on an elasto-static analysis combined with numerical analysis is suggested to compute this term. This new model supplies also the accurate pressure distribution within the container.

Subject Keywords

Mechanical engineering, Metal forming, Cold forging, Forward rod extrusion, Analytical force prediction, Finite element method

URI

https://hdl.handle.net/11511/67024

Journal

ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING

Collections

Department of Mechanical Engineering, Article

Suggestions

OpenMETU
Core

Analysis of thin walled open section tapered beams using hybrid stress finite element method Akman, Mehmet Nazım; Oral, Süha; Department of Mechanical Engineering (2008) In this thesis, hybrid stress finite element is formulated for the analysis of the isotropic, thin walled, open section beams with variable cross sections. The beam element has two nodes each having seven degrees of freedom. Assumption of stress field is sufficient to determine the element stiffness matrix. Axial, flexural and torsional effects are taken into account in the analysis. The methodology can be applied both to the tapered and the uniform beams. Throughout this study, firstly element cross-sectio...
On-Line Application of SHEM by Particle Swarm Optimization to Grid-Connected, Three-Phase, Two-Level VSCs with Variable DC Link Voltage Guvengir, Umut; ÇADIRCI, IŞIK; Ermiş, Muammer (2018-08-01) This paper is devoted to an otablen-line application of the selective harmonic elimination method (SHEM) to three-phase, two-level, grid-connected voltage source converters (VSCs) by particle swarm optimization (PSO). In such systems, active power can be controlled by the phase shift angle, and reactive power by the modulation index, against variations in the direct current (DC) link voltage. Some selected, low-odd-order harmonic components in the line-to-neutral output voltage waveforms are eliminated by c...
Implementation and assessment of modern shock-capturing schemes for hypersonic viscous flows Şahin, Çağatay; Baran, Özgür Uğraş; Atik, Hediye; Department of Mechanical Engineering (2022-8-22) Spatially second order accurate Finite Volume Method (FVM) is the most preferred method in Computational Fluid Mechanics (CFD) with its acceptable results in short computation times. FVM's accuracy heavily relies on the particular numerical scheme with which the fluxes are evaluated. Despite the maturity of traditional flux schemes today, simulations of a viscous hypersonic ﬂow are still challenging. Since these cases involve strong shock waves and viscous layers with non-linear gradients, appropriate shock...
ELECTRICAL-IMPEDANCE TOMOGRAPHY OF TRANSLATIONALLY UNIFORM CYLINDRICAL OBJECTS WITH GENERAL CROSS-SECTIONAL BOUNDARIES IDER, YZ; Gençer, Nevzat Güneri; ATALAR, E; TOSUN, H (1990-03-01) An algorithm is developed for electrical impedance tomography (EIT) of finite cylinders with general cross-sectional boundaries and translationally uniform conductivity distributions. The electrodes for data collection are assumed to be placed around a crosssectional plane; therefore the axial variation of the boundary conditions and also the potential field are expanded in Fourier series. For each Fourier component a two-dimensional (2-D) partial differential equation is derived. Thus the 3-D forward probl...
Quantitative electrostatic force measurement in AFM JEFFERY, Steve; Oral, Ahmet; Pethica, John B. (2000-04-02) We describe a method for measuring forces in the atomic force microscope (AFM), in which a small amplitude oscillation(similar to 1 Angstrom(p-p)) is applied to a stiff(similar to 40 N/m) cantilever below its first resonant frequency, and the force gradient is measured directly as a function of separation. We have used this instrument to measure electrostatic forces by applying an ac voltage between the tip and the sample, and observed a variation in contact potential difference with separation. We also sho...

Citation Formats

M. Ocal, N. Egemen, and A. Tekkaya, “Assessment and improvement of elementary force computations for cold forward rod extrusion,” ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING, pp. 83–102, 2005, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/67024.