Atanas Kochov - Academia.edu (original) (raw)

Papers by Atanas Kochov

Research paper thumbnail of Production of complex parts by deep drawing - deformation analysis

The object of this paper is the deformation analysis aimed to determine the stability of the tech... more The object of this paper is the deformation analysis aimed to determine the stability of the technological process of deep drawing complex steel sheet parts. The forming limit diagram is described. Analysis of the forming limit curves is made, whereas criteria for limit deformation are considered the moment when the maximum of even deformation is accomplished and the moment when crack occurs in the material. A procedure for determination of forming limit curves is elaborated. Forming limit curves are experimentally determined the according to the both criteria for the steel sheet C0147 (RSt 13 according to DIN 17006). Finally, it is presented how this can be used practically.

Research paper thumbnail of Analysis of additive manufacturing technology input parameters in manufacturing of bolus

Mechanical Engieneering – Scientific Journal

Research paper thumbnail of Soil pollution from exhaust gases and waste substances from light vehicles

Research paper thumbnail of Conformal Cooling Channels in Injection Molding Tools – Design Considerations

This scientific paper presents the research conducted for defining the characteristics of the con... more This scientific paper presents the research conducted for defining the characteristics of the conformal cooling systems used in molds for injection molding processes (IMP). By utilizing laser-sintering additive manufacturing (AM) technologies, this type of cooling systems could be used to minimize the cooling and cycle times in the IMP’s and provide a homogeneous cooling necessary to maintain a consistent quality of the part. The paper also presents an overview of the AM technologies used in manufacturing conformal cooling molds and the main guidelines for designing these cooling systems. The research shows that the efficiency of these channels is based on the channel system’s design; and for plastic parts with a lower complexity the improved temperature distribution compared to conventional cooling systems could be negligent. The research is conducted by using Finite Element Analysis (FEA) and CAD modeling to compare different conformal shapes, as well as their cooling efficiency o...

Research paper thumbnail of Production of complex parts by deep drawing - deformation analysis

The object of this paper is the deformation analysis aimed to determine the stability of the tech... more The object of this paper is the deformation analysis aimed to determine the stability of the technological process of deep drawing complex steel sheet parts. The forming limit diagram is described. Analysis of the forming limit curves is made, whereas criteria for limit deformation are considered the moment when the maximum of even deformation is accomplished and the moment when crack occurs in the material. A procedure for determination of forming limit curves is elaborated. Forming limit curves are experimentally determined the according to the both criteria for the steel sheet C0147 (RSt 13 according to DIN 17006). Finally, it is presented how this can be used practically.

Research paper thumbnail of Influence of the size of an hole derived in the initial material on the drawing workability of the cold-rolled metal sheets

Research paper thumbnail of Sustainable Improvement of the Energy Efficiency of an Existing Building

Research paper thumbnail of Influence of the surface quality due to a hole derived in initial material processing of cold sheets with drawing

Research paper thumbnail of The Application of Additive Manufacturing in Developing 3D Printed Prostethics and Orthotic Devices

This paper covers the advanced Additive Manufacturing (AM) techniques used to fabricate prostethi... more This paper covers the advanced Additive Manufacturing (AM) techniques used to fabricate prostethic and orthotic devices. It reviews the available literature and summarizes the advances in medicine, computing and engineering that have led to the development of currently available prostheses. Some of the open-source bionic hands and other available prosthesis are shown, as well as the technologies and materials which are used to manufacture the parts. Since prototyping, combined with the possibility for easy maintenance and repair, is very attractive for prosthesis design, as a conclusion we summarize and discuss some of the key areas that could lead to improvements in bionic limb functionality and use.

Research paper thumbnail of Tensile Strength of Carbon Fiber

Tehnički glasnik

Carbon fiber is a material with a vast area of utilization. When combined with a resin, we get a ... more Carbon fiber is a material with a vast area of utilization. When combined with a resin, we get a composite, which provides great mechanical properties, has low mass and can be utilized in many different applications. Carbon fiber cloth can be found in a wide range of forms and shapes, differing from weight to the shape of their weave. Manufacturing a composite part can be achieved with a variety of techniques and processes, each of them having advantages and disadvantages over the other. One of the most common process for producing composite parts is the open moulded hand lay-up process. This process is economically viable, has low cost for equipment, and can produce parts with satisfactory results. A composite sheet is manufactured using the hand lay-up process. Three testing samples are taken out from the composite sheet, and their tensile strength is determined using the ASTM D3039 standard.

Research paper thumbnail of Applications of AHP Methodology for Decision-Making in Cleaner Production Processes

Research paper thumbnail of Energy Scenarios for South Eastern Europe: A close look into the Western Balkans

"The Energy Scenarios for South East Europe" thematic seminar took place on the 15th of... more "The Energy Scenarios for South East Europe" thematic seminar took place on the 15th of December 2015 in Vienna, Austria. The workshop was organized by Institute of Energy and Transport of the European Commission's Joint Research Centre (JRC-IET), hosted by the Energy Community Secretariat (ECS) and sponsored by the Directorate-General for Neighbourhood and Enlargement Negotiations (DG-NEAR) in the framework of the Travel Accommodation and Conference facility for Western Balkans and Turkey, a programme of dissemination activities organised by the Commission in the EU or the beneficiary country in connection with the enlargement process and the pre-accession strategy. The aim of the workshop was to bring together representatives from think tanks, scientific institutes, the academia and the private sector with government officials, the national statistical agencies and the local TSO representatives from the Western Balkan region to exchange views on potential energy technology deployment scenarios that could facilitate a low carbon development pathway for the enlargement countries, but also exchange on the methodologies utilized and identify challenges as well as potential pitfalls in this process. The workshop included three sessions of specific thematic focus. The first session provided the "regional picture" with forecasts on the development of the energy and power systems in the western Balkans. The second session discussed case studies on low carbon development trajectories for specific countries in the region; and the third session explored the role of particular technologies in this context. This report comprises of long abstracts from the workshop presentations and closes with a chapter on conclusions and recommendations that resulted from the discussion sessions.

Research paper thumbnail of The Importance of SD Goals Indicators 7, 8, 9 and 12 in the Industry Development by Using Multi Criteria and Decision Making Method

Tehnički glasnik, 2020

Sustainable Development and Decision Making are just two of the many processes that affect the in... more Sustainable Development and Decision Making are just two of the many processes that affect the industry sector. SDG7, SDG8, SDG9 and SDG 12 as four goals of sustainable development show the indicators we have to deal with, given that the energy, industry, economy and production are closely connected. This research focuses on promoting sustainable development in the industry, by testing very important indicators using the MCDM method. Our analysis was carried out with the help of a multi-criteria decision-making method - the Hierarchical Analytical Process. Through this method, we have identified specific areas that need improvement, the importance of the indicators separately, ranking so by their importance and impact in the industry, economy and production.

Research paper thumbnail of Application of Compromise Programming in the Energy Generation Planning

Tehnički glasnik, 2021

The need for the right electricity planning is closely related to the analysis that has to be don... more The need for the right electricity planning is closely related to the analysis that has to be done on its generating capacity. Of course, in order to make such planning, the choice of the method by which the process is carried out must be considered. The inclusion of multiple objectives (goals) enables us to create models that are useful in researching and expanding electricity generation systems. Compromised programming used in this paper aims to find compromise solutions among different conflicting objectives in the electricity generation system. One such case is the goal of minimizing the cost and CO2 emissions. Using this logic, the paper deals with an example of electricity generation planning for a given region.

Research paper thumbnail of Risks and Safety Issues Related to Use of Electric and Hybrid Vehicles

Nowadays hybrid vehicles take increasing share of new road vehicles, but also the electric vehicl... more Nowadays hybrid vehicles take increasing share of new road vehicles, but also the electric vehicles have continuous development which is a sign of a serious beginning of new era of their use. The goals of introducing of these vehicles include lowering of the negative impact on the environment and also reducing of their operational costs. Together with the mentioned trends, there are some specifics related to the risks of using this type of vehicles. This paper gives the key elements related to the development of hybrid and electric vehicles with emphasis of the general distinctions in terms of conventional vehicles with internal combustion engines. The paper has focus on risk identification and hazards that can arise from hybrid and electric vehicles, which are specifically related to their technical differences from conventional vehicles with internal combustion engine. Those risks exist when the vehicles are in use, but also even when the vehicle is not in operation. There is also...

Research paper thumbnail of of ENGINEERING-HUNEDOARA, ROMANIA 115 1. METAL MATRIX COMPOSITES AS TOOLS MATERIAL FOR THE DEEP DRAWING

In order to improve the strength and high-temperature properties of sintered iron, metal matrix i... more In order to improve the strength and high-temperature properties of sintered iron, metal matrix iron-Alumina (Al 2 O 3) composite material has been studied. In the present investigation, iron powder added by 0-8 Wgt % Al 2 O 3 powder where selected for the study. Powders where mixed, compacted and subsequently sintered at 1150 o C in laboratory tube furnace, under an endo gas atmosphere. Composite material properties were evaluated. The outcome results is that 4 vol % Al 2 O 3 is the optimal percentage of the Alumina to obtain superior properties of the metal matrix composite. The deep drawing die and punch have been designed by using metal matrix composite and experimentally tested. INTRODUCTION Sintered iron components are used for various commercial applications. However, inferior strength is a limitation of sintered straight iron powder metallurgy products in many applications. Therefore, it is very important to increase the strength of straight iron powder metallurgy products. ...

Research paper thumbnail of Methodology of Reverse Engineering Implemented in the Process of Digitalization and Conservation of Wooden Carvings

Tehnički glasnik, 2022

The purpose of this paper is to present the benefits of reverse engineering when applied to cultu... more The purpose of this paper is to present the benefits of reverse engineering when applied to cultural heritage i.e. digitalizing and duplicating an artwork in lack of original documentation, drawings, or computer models; Usage of different methods for 3D scanning, reverse engineering softwares with a smart combination of history-based CAD with 3D scan data processing, for preparing the obtained 3D model for future production use; Describing tools and machines for rapid prototyping, materials used and the feasibility of its completion; Set of tools that provide opportunities for new projects and innovations but are also of cultural and historical significance.

Research paper thumbnail of Modeling and Simulation of High-Voltage Transmission Line Insulators in a Virtual and Laboratory Environment

Machine and Industrial Design in Mechanical Engineering, 2022

Research paper thumbnail of Experimental Analysis for Defining Mechanical Properties of Steel Sheet Metal on Different Material Thickness

Machine and Industrial Design in Mechanical Engineering, 2022

Research paper thumbnail of The Importance of SD Goals Indicators 7, 8, 9 and 12 in the Industry Development by Using Multi Criteria and Decision Making Method

Tehnički glasnik, 2020

Sustainable Development and Decision Making are just two of the many processes that affect the in... more Sustainable Development and Decision Making are just two of the many processes that affect the industry sector. SDG7, SDG8, SDG9 and SDG 12 as four goals of sustainable development show the indicators we have to deal with, given that the energy, industry, economy and production are closely connected. This research focuses on promoting sustainable development in the industry, by testing very important indicators using the MCDM method. Our analysis was carried out with the help of a multi-criteria decision-making method - the Hierarchical Analytical Process. Through this method, we have identified specific areas that need improvement, the importance of the indicators separately, ranking so by their importance and impact in the industry, economy and production.

Research paper thumbnail of Production of complex parts by deep drawing - deformation analysis

The object of this paper is the deformation analysis aimed to determine the stability of the tech... more The object of this paper is the deformation analysis aimed to determine the stability of the technological process of deep drawing complex steel sheet parts. The forming limit diagram is described. Analysis of the forming limit curves is made, whereas criteria for limit deformation are considered the moment when the maximum of even deformation is accomplished and the moment when crack occurs in the material. A procedure for determination of forming limit curves is elaborated. Forming limit curves are experimentally determined the according to the both criteria for the steel sheet C0147 (RSt 13 according to DIN 17006). Finally, it is presented how this can be used practically.

Research paper thumbnail of Analysis of additive manufacturing technology input parameters in manufacturing of bolus

Mechanical Engieneering – Scientific Journal

Research paper thumbnail of Soil pollution from exhaust gases and waste substances from light vehicles

Research paper thumbnail of Conformal Cooling Channels in Injection Molding Tools – Design Considerations

This scientific paper presents the research conducted for defining the characteristics of the con... more This scientific paper presents the research conducted for defining the characteristics of the conformal cooling systems used in molds for injection molding processes (IMP). By utilizing laser-sintering additive manufacturing (AM) technologies, this type of cooling systems could be used to minimize the cooling and cycle times in the IMP’s and provide a homogeneous cooling necessary to maintain a consistent quality of the part. The paper also presents an overview of the AM technologies used in manufacturing conformal cooling molds and the main guidelines for designing these cooling systems. The research shows that the efficiency of these channels is based on the channel system’s design; and for plastic parts with a lower complexity the improved temperature distribution compared to conventional cooling systems could be negligent. The research is conducted by using Finite Element Analysis (FEA) and CAD modeling to compare different conformal shapes, as well as their cooling efficiency o...

Research paper thumbnail of Production of complex parts by deep drawing - deformation analysis

The object of this paper is the deformation analysis aimed to determine the stability of the tech... more The object of this paper is the deformation analysis aimed to determine the stability of the technological process of deep drawing complex steel sheet parts. The forming limit diagram is described. Analysis of the forming limit curves is made, whereas criteria for limit deformation are considered the moment when the maximum of even deformation is accomplished and the moment when crack occurs in the material. A procedure for determination of forming limit curves is elaborated. Forming limit curves are experimentally determined the according to the both criteria for the steel sheet C0147 (RSt 13 according to DIN 17006). Finally, it is presented how this can be used practically.

Research paper thumbnail of Influence of the size of an hole derived in the initial material on the drawing workability of the cold-rolled metal sheets

Research paper thumbnail of Sustainable Improvement of the Energy Efficiency of an Existing Building

Research paper thumbnail of Influence of the surface quality due to a hole derived in initial material processing of cold sheets with drawing

Research paper thumbnail of The Application of Additive Manufacturing in Developing 3D Printed Prostethics and Orthotic Devices

This paper covers the advanced Additive Manufacturing (AM) techniques used to fabricate prostethi... more This paper covers the advanced Additive Manufacturing (AM) techniques used to fabricate prostethic and orthotic devices. It reviews the available literature and summarizes the advances in medicine, computing and engineering that have led to the development of currently available prostheses. Some of the open-source bionic hands and other available prosthesis are shown, as well as the technologies and materials which are used to manufacture the parts. Since prototyping, combined with the possibility for easy maintenance and repair, is very attractive for prosthesis design, as a conclusion we summarize and discuss some of the key areas that could lead to improvements in bionic limb functionality and use.

Research paper thumbnail of Tensile Strength of Carbon Fiber

Tehnički glasnik

Carbon fiber is a material with a vast area of utilization. When combined with a resin, we get a ... more Carbon fiber is a material with a vast area of utilization. When combined with a resin, we get a composite, which provides great mechanical properties, has low mass and can be utilized in many different applications. Carbon fiber cloth can be found in a wide range of forms and shapes, differing from weight to the shape of their weave. Manufacturing a composite part can be achieved with a variety of techniques and processes, each of them having advantages and disadvantages over the other. One of the most common process for producing composite parts is the open moulded hand lay-up process. This process is economically viable, has low cost for equipment, and can produce parts with satisfactory results. A composite sheet is manufactured using the hand lay-up process. Three testing samples are taken out from the composite sheet, and their tensile strength is determined using the ASTM D3039 standard.

Research paper thumbnail of Applications of AHP Methodology for Decision-Making in Cleaner Production Processes

Research paper thumbnail of Energy Scenarios for South Eastern Europe: A close look into the Western Balkans

"The Energy Scenarios for South East Europe" thematic seminar took place on the 15th of... more "The Energy Scenarios for South East Europe" thematic seminar took place on the 15th of December 2015 in Vienna, Austria. The workshop was organized by Institute of Energy and Transport of the European Commission's Joint Research Centre (JRC-IET), hosted by the Energy Community Secretariat (ECS) and sponsored by the Directorate-General for Neighbourhood and Enlargement Negotiations (DG-NEAR) in the framework of the Travel Accommodation and Conference facility for Western Balkans and Turkey, a programme of dissemination activities organised by the Commission in the EU or the beneficiary country in connection with the enlargement process and the pre-accession strategy. The aim of the workshop was to bring together representatives from think tanks, scientific institutes, the academia and the private sector with government officials, the national statistical agencies and the local TSO representatives from the Western Balkan region to exchange views on potential energy technology deployment scenarios that could facilitate a low carbon development pathway for the enlargement countries, but also exchange on the methodologies utilized and identify challenges as well as potential pitfalls in this process. The workshop included three sessions of specific thematic focus. The first session provided the "regional picture" with forecasts on the development of the energy and power systems in the western Balkans. The second session discussed case studies on low carbon development trajectories for specific countries in the region; and the third session explored the role of particular technologies in this context. This report comprises of long abstracts from the workshop presentations and closes with a chapter on conclusions and recommendations that resulted from the discussion sessions.

Research paper thumbnail of The Importance of SD Goals Indicators 7, 8, 9 and 12 in the Industry Development by Using Multi Criteria and Decision Making Method

Tehnički glasnik, 2020

Sustainable Development and Decision Making are just two of the many processes that affect the in... more Sustainable Development and Decision Making are just two of the many processes that affect the industry sector. SDG7, SDG8, SDG9 and SDG 12 as four goals of sustainable development show the indicators we have to deal with, given that the energy, industry, economy and production are closely connected. This research focuses on promoting sustainable development in the industry, by testing very important indicators using the MCDM method. Our analysis was carried out with the help of a multi-criteria decision-making method - the Hierarchical Analytical Process. Through this method, we have identified specific areas that need improvement, the importance of the indicators separately, ranking so by their importance and impact in the industry, economy and production.

Research paper thumbnail of Application of Compromise Programming in the Energy Generation Planning

Tehnički glasnik, 2021

The need for the right electricity planning is closely related to the analysis that has to be don... more The need for the right electricity planning is closely related to the analysis that has to be done on its generating capacity. Of course, in order to make such planning, the choice of the method by which the process is carried out must be considered. The inclusion of multiple objectives (goals) enables us to create models that are useful in researching and expanding electricity generation systems. Compromised programming used in this paper aims to find compromise solutions among different conflicting objectives in the electricity generation system. One such case is the goal of minimizing the cost and CO2 emissions. Using this logic, the paper deals with an example of electricity generation planning for a given region.

Research paper thumbnail of Risks and Safety Issues Related to Use of Electric and Hybrid Vehicles

Nowadays hybrid vehicles take increasing share of new road vehicles, but also the electric vehicl... more Nowadays hybrid vehicles take increasing share of new road vehicles, but also the electric vehicles have continuous development which is a sign of a serious beginning of new era of their use. The goals of introducing of these vehicles include lowering of the negative impact on the environment and also reducing of their operational costs. Together with the mentioned trends, there are some specifics related to the risks of using this type of vehicles. This paper gives the key elements related to the development of hybrid and electric vehicles with emphasis of the general distinctions in terms of conventional vehicles with internal combustion engines. The paper has focus on risk identification and hazards that can arise from hybrid and electric vehicles, which are specifically related to their technical differences from conventional vehicles with internal combustion engine. Those risks exist when the vehicles are in use, but also even when the vehicle is not in operation. There is also...

Research paper thumbnail of of ENGINEERING-HUNEDOARA, ROMANIA 115 1. METAL MATRIX COMPOSITES AS TOOLS MATERIAL FOR THE DEEP DRAWING

In order to improve the strength and high-temperature properties of sintered iron, metal matrix i... more In order to improve the strength and high-temperature properties of sintered iron, metal matrix iron-Alumina (Al 2 O 3) composite material has been studied. In the present investigation, iron powder added by 0-8 Wgt % Al 2 O 3 powder where selected for the study. Powders where mixed, compacted and subsequently sintered at 1150 o C in laboratory tube furnace, under an endo gas atmosphere. Composite material properties were evaluated. The outcome results is that 4 vol % Al 2 O 3 is the optimal percentage of the Alumina to obtain superior properties of the metal matrix composite. The deep drawing die and punch have been designed by using metal matrix composite and experimentally tested. INTRODUCTION Sintered iron components are used for various commercial applications. However, inferior strength is a limitation of sintered straight iron powder metallurgy products in many applications. Therefore, it is very important to increase the strength of straight iron powder metallurgy products. ...

Research paper thumbnail of Methodology of Reverse Engineering Implemented in the Process of Digitalization and Conservation of Wooden Carvings

Tehnički glasnik, 2022

The purpose of this paper is to present the benefits of reverse engineering when applied to cultu... more The purpose of this paper is to present the benefits of reverse engineering when applied to cultural heritage i.e. digitalizing and duplicating an artwork in lack of original documentation, drawings, or computer models; Usage of different methods for 3D scanning, reverse engineering softwares with a smart combination of history-based CAD with 3D scan data processing, for preparing the obtained 3D model for future production use; Describing tools and machines for rapid prototyping, materials used and the feasibility of its completion; Set of tools that provide opportunities for new projects and innovations but are also of cultural and historical significance.

Research paper thumbnail of Modeling and Simulation of High-Voltage Transmission Line Insulators in a Virtual and Laboratory Environment

Machine and Industrial Design in Mechanical Engineering, 2022

Research paper thumbnail of Experimental Analysis for Defining Mechanical Properties of Steel Sheet Metal on Different Material Thickness

Machine and Industrial Design in Mechanical Engineering, 2022

Research paper thumbnail of The Importance of SD Goals Indicators 7, 8, 9 and 12 in the Industry Development by Using Multi Criteria and Decision Making Method

Tehnički glasnik, 2020

Sustainable Development and Decision Making are just two of the many processes that affect the in... more Sustainable Development and Decision Making are just two of the many processes that affect the industry sector. SDG7, SDG8, SDG9 and SDG 12 as four goals of sustainable development show the indicators we have to deal with, given that the energy, industry, economy and production are closely connected. This research focuses on promoting sustainable development in the industry, by testing very important indicators using the MCDM method. Our analysis was carried out with the help of a multi-criteria decision-making method - the Hierarchical Analytical Process. Through this method, we have identified specific areas that need improvement, the importance of the indicators separately, ranking so by their importance and impact in the industry, economy and production.