Browsing by Author "Erden, A"

Now showing 1 - 5 of 5

Citation - WoS: 42
Citation - Scopus: 52
A Comparative Study on the Surface Integrity of Plastic Mold Steel Due To Electric Discharge Machining
(Springer, 2005) Ekmekci, B; Elkoca, O; Erden, A; Department of Mechatronics Engineering; 01. Atılım University
The violent nature of the electric discharge machining (EDM) process leads to a unique structure. on the surface of a machined part. In this study, the influence of electrode material and type of dielectric liquid on the surface integrity of plastic mold steel samples is investigated. The results have shown that regardless of the tool electrode and the dielectric liquid, the white layer is formed on machined surfaces. This layer is composed of cementite (Fe3C) and martensite distributed in retained austenite matrix forming dendritic structures, due to rapid solidification of the molten metal, if carbon-based dielectric liquid is used. The intensity of cracking increases at high pulse durations and low pulse currents. Cracks on the EDM surfaces have been found to follow the pitting arrangements with closed loops and to cross perpendicularly with radial cracks and continue to propagate when another discharge takes place, in the neighborhood. The amount of retained austenite phase and the intensity of microcracks have found to be much less in the white layer of the samples machined in de-ionized water dielectric liquid. The number of globule appendages attached to the surface increased when a carbon-based tool electrode material or a dielectric liquid was used during machining.
Creativity
(international Academic Publishers Ltd, 2005) Güroglu, S; Erden, A; Akbulut, D; Özgüç, B; Department of Mechatronics Engineering; 01. Atılım University
This study aims at developing an evaluation measure to identify creative solutions generated in evolutionary design process. This measure also guides the process to produce original solution in early phases of design activity.
An Evolutionary Approach for Functional Level Conceptual Design of Products
(Univ Zagreb, Faculty Mechanical Engineering & Naval Architecture, 2004) Güroglu, S; Erden, A; Department of Mechatronics Engineering; 01. Atılım University
[No Abstract Available]
Citation - WoS: 6
Citation - Scopus: 5
A Petri Net Approach To Behavioural Simulation of Design Artefacts With Application To Mechatronic Design
(Springer Heidelberg, 2003) Erden, Z; Erden, A; Erkmen, AM; Mechatronics Engineering; Department of Mechatronics Engineering; 15. Graduate School of Natural and Applied Sciences; 06. School Of Engineering; 01. Atılım University
A Petri net-based design inference network (PNDN) architecture is presented in this paper. The network models the logical behaviour of any design artefact developed by designers at the conceptual design level by representing the subfunctions and their inter-relationships to perform a required overall function. The theoretical framework in developing the PNDN is based on the improved theory of Petri nets and hybrid automata. The theoretical PNDN architecture was implemented in a C++ based software called the design network simulator (DNS). The logical behaviour of a design artefact is modelled through the token flow within the PNDN. The token flow model is developed both for deterministic and nondeterministic PNDN, which involves uncertainties. In this paper we present the mathematical formalism of the deterministic token flow through the PNDN. We also provide a conceptual design example in order to explain the application of our theoretical architecture for structuring the PNDN.
Citation - WoS: 54
Citation - Scopus: 62
Residual stress state and hardness depth in electric discharge machining: De-ionized water as dielectric liquid
(Taylor & Francis inc, 2005) Ekmekci, B; Elkoca, O; Tekkaya, AE; Erden, A; Manufacturing Engineering; Department of Mechatronics Engineering; 06. School Of Engineering; 01. Atılım University
Procedures and results of experimental work to measure residual stresses and hardness depth in electric discharge machined surfaces are presented. Layer removal method is used to express the residual stress profile as a function of depth caused by a die sinking type EDM. Thin stressed layers are removed from machined samples by electrochemical machining. Corresponding deformations due to stress relaxation are recorded for each removal to determine the stress profile from elasticity theory. The relational dependence of the machining parameters with residual stresses is obtained and a semi-empirical model is proposed for plastic mold steel for de-ionized water as dielectric liquid. These stresses are found to be increasing rapidly with respect to depth, attaining to its maximum value, around the yield strength, and then fall rapidly to compressive residual stresses in the core of the material since the stresses within plastically deformed layers are equilibrated with elastic stresses.