Lutu Popp - Academia.edu (original) (raw)

Papers by Lutu Popp

This article explores the process of calibrating the properties of DC01 materials for finite elem... more This article explores the process of calibrating the properties of DC01 materials for finite element analysis using ABAQUS and Isight. Precise calibration of yield strength and tensile strength is crucial for accurately modeling material behavior under various loading conditions. The article details the sample preparation process, deformation measurements, and tensile tests to obtain experimental data. These data are then used to calibrate the DC01 material model in ABAQUS with the assistance of Isight, ensuring that the simulations accurately reflect realworld behavior. The results indicate the success of the calibration, facilitating the design and testing of products in a predictive virtual environment. Precise calibration is essential for predicting material behavior in real-world conditions and minimizing the risk of implementation failures.

This paper presents the results of some experimental tests concerning the basalt parts submitted ... more This paper presents the results of some experimental tests concerning the basalt parts submitted to specific thermic stresses, and resulted from the operation of machine tools. The tests were also involved in similar cast iron parts, in order to compare the results and to establish the possibility of using basalt in building mechine tools.

Annals of the Oradea University: Fascicle Management and Technological Engineering, 2011

The paper describes an interactive decision support framework designed to aid decision makers in ... more The paper describes an interactive decision support framework designed to aid decision makers in selecting the most appropriate machines for a flexible manufacturing system (FMS). The framework can be used in the prescreening stage of the planning process, after a decision has been made, in principle, to build an FMS. The framework mainly consists of two parts. The first part (this paper) is called the prescreening stage, which narrows down all possible configurations by using the analytic hierarchy process..

Applied Mechanics and Materials, Jun 1, 2016

After the first time invention of Kanban system by Ohno Taiichi [1], Kanban system is becoming mo... more After the first time invention of Kanban system by Ohno Taiichi [1], Kanban system is becoming more and more famous in industries and nevertheless its importance and implementation is increasing faster than ever before. Main objective is to address this question thoroughly, how knowledge base Kanban system can be useful in future. This research work shows a modeling approach of Kanban system implementation to improve and meet the requirement of knowledge by implementing Kanban system using just in time concept given by Ohno Taiichi for academic institution. It also describe how can this system be implemented and how can we benefit from this system in a different way. Its advantages and disadvantages are also discussed this paper.

Applied Mechanics and Materials, May 1, 2015

The objective of this paper is the design of some elements of equipment for the closing of shock ... more The objective of this paper is the design of some elements of equipment for the closing of shock absorbers through the rolling method with a wide range of tank tube lengths and also of the functional structure of the equipment with the shifting/settlement of the damper in the sertization process. Closing damper device is intended by the deflection of the upper reservoir tube. In the paper, the author present his concerns regarding the study and design (parts CAD, the crimping devices) of this equipment which use this proposed technology [1, 2] for the crimping rolling method for shock absorbers reservoir cylinders.

MATEC Web of Conferences

Although research on incremental forming process began a few decades ago, it is still a process i... more Although research on incremental forming process began a few decades ago, it is still a process in development phase. Single point incremental forming is a simple process and the deformation of the sheet blank is done with the help of a punch that follows a known toolpath. In the case of this process, one important aspect is the prediction of material failure. To achieve this with the help of a finite element analysis, a series of experiments were performed to determine the forming limit diagram. In this paper, an attempt has been made to determine the forming limit diagram for the AA1050 aluminum alloy. The experiments were performed with the help of an industrial robot, KUKA KR 210-2, thus the part can be measured with an optical measuring instrument obtaining the major and minor strain from forming limit diagram.

MATEC Web of Conferences, 2019

Single point incremental forming is a process which is primarily used for prototyping, small seri... more Single point incremental forming is a process which is primarily used for prototyping, small series production and unique parts. This procedure shows a high potential in the development of complex shape parts where the time of the execution does not play an important role. Among the applications of this process are the execution of various medical prostheses, such as: knee prostheses and cranial implants. The aim of this paper is to determine the forces which take place during the manufacture process of an cranial implant, as well as the thinning of the material through the help of finite element analysis. After the numerical simulation, from the results obtained it is possible to observe the behaviour of the material at different forces which appear during the deformation process. In addition, in this paper will be presented considerations about the thinning of the material used for the cranial implant.

The Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science, 2020

Basalt is a material available in big quantities in nature. It has a low price and can be used in... more Basalt is a material available in big quantities in nature. It has a low price and can be used in various domains. It can be relatively easily extracted from natural deposits and processed by means of melting. Melted and recrystallized basalt has demonstrated promising behavior with regards of its use in manufacturing, as reported in the literature. This paper presents the results of an experimental study on the determination of the modulus of elasticity of molten and recrystallized basalt by the method of resistive electrical tensometry and to validate the result and by simulation using finite elements method. Testing methodology, experimental test, data records, data processing and resulting conclusions are presented in the paper.

This paper presents some aspects of diagnosis bearings in preventive maintenance and the importan... more This paper presents some aspects of diagnosis bearings in preventive maintenance and the importance of bearing repair as an alternative to replacing them. Bearing repair is not a new concept, nor has it changed a great deal over the years. Repairing damaged bearings is a precise science that has been fine-tuned over time through careful and gradual enhancements to provide superior results. Knowing and understanding the value of bearing repair means knowing what repair can do, when to use it, and where to get it done.

Acta Universitatis Cibiniensis. Technical Series

Nowadays, there is a high demand for rapid prototyping parts and for products manufactured throug... more Nowadays, there is a high demand for rapid prototyping parts and for products manufactured through plastic cold deformation. Incremental forming process is one of many which presents numerous advantages for fast production of complex shape parts. The purpose of this study is to develop a numerical model through finite element analysis to simulate the incremental forming process. For this analysis a variable wall angle part (VWA) which ranges from a 45° wall angle at the higher base of frustrum cone to a 70° wall angle at the base of the shape was proposed. The numerical model showed where the maximum strains are localized, how big the forces are during the process and how much the material thinned. Although the model does not indicate a possible failure of the material, the integrity of the structural stiffness was altered due to a minimum thickness reached of just 0.26mm.

Acta Universitatis Cibiniensis. Technical Series

In general, a large part of the time is devoted to the design and production of reliable parts wh... more In general, a large part of the time is devoted to the design and production of reliable parts where extensive knowledge is required for the design engineers to come up with an optimal solution for the tooling and sheet metal forming processes. Most of the time, the principle of trial and error is used to get the desired shapes for the products. This is because the prediction of deformations occurring in sheet metal elements is not available and is highly dependent on the geometry of the part, the tools and the deformation process. Prediction is limited by the proper location of necking, shear breakage, and puckering of the material. Searching for a robust deformation process by trial and error is expensive and inefficient. The use of numerical simulations provides engineers with an alternative efficiency for developing a tool and process to produce quality parts in a more efficient and lower cost. Computer simulation is an extension of theoretical science that is based on mathemati...

This paper present some researches concerning the stability in use of cold-working machines drive... more This paper present some researches concerning the stability in use of cold-working machines driven with electro-hydraulic servo-systems such as hydraulic linear amplifiers. In this work, a complex synthesis of electro-hydraulic servo-systems used in driving machines and industrial robots is also presented. The researches conducted upon a particular system, reveal the optimum design elements for obtaining a good behaviour in use, subsequently a good stability in use.

In this paper it is described a generic system architecture for increasing the flexibility of man... more In this paper it is described a generic system architecture for increasing the flexibility of manufacturing systems; there is also briefly explained how to configure the different resource modules that actually control the tasks of the physical device and put together a work cell consisting of other FMS resources. Using the principles of distributed object technology there could be implemented each resource in the work cell as a distributed object. A resource, modelled as a distributed object, has a well-defined interface, describing the data and the methods that it supports. A distributed object can execute either on the same computer or another networked computer. Finally, an example on building a FMS using a hierarchical approach is presented.

This paper presents the main CAD – computer aided design – elements of an automatic transfer syst... more This paper presents the main CAD – computer aided design – elements of an automatic transfer system, air-driven, destined for some charging/disposal operation of some work posts for the assembly/testing of the subsystem-carcass, in agreement with Compa SA Sibiu. The carcass, the manipulated subsystem, is part of the turbocompressor assembly (compressor + turbine) – of a testing equipment. The analyzed manipulator for the handling of 7 work posts, with direct application to the charging with disc type subsystems from subsystem palletainers, can be generalized to the serving, to the purpose of testing, of many such posts in a automatised assembly line and carcass checking.

The present research refers to the analysis and the synthesis of an electro-hydraulic servosystem... more The present research refers to the analysis and the synthesis of an electro-hydraulic servosystem, specific to heavy machine tools. It is presented the construction and the functionality of the servosystem, the physical elements of design and its mathematical modelling, the correspondent transfer function and the results of the research, with the afferent restrictions.

MATEC Web of Conferences, 2021

The aim of this paper was to carry out a theoretical (numerical) scientific research on the behav... more The aim of this paper was to carry out a theoretical (numerical) scientific research on the behavior of cast and recrystallized basalt, in order to use it as a material in the manufacture of structural elements of machine tools. A unitary methodology has been established for studying the eigenfrequency of structural elements for machine tools by the finite element method. Two basalt structural elements (beam type and plate type) were modeled, which were also made physically, and with the help of the COSMOS / Mark finite element program, the eigenfrequencies of the models was studied.

ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2014

The paper presents aspects regarding the development of a mobile robot (on wheels) fitted with AT... more The paper presents aspects regarding the development of a mobile robot (on wheels) fitted with ATmega328P-PV microcontroller and infrared and ultrasound sensors for detection. The robot programming elements and the test of its characteristics and performance are also highlighted. The robot is able to pursue an autonomously route determined in advance and avoid any obstacles which might arise in its path, returning then to the default route.

MATEC Web of Conferences, 2017

Basalt is a material available in big quantities in nature. It has a low price and can be used in... more Basalt is a material available in big quantities in nature. It has a low price and can be used in various domains. It can be relatively easily extracted from natural deposits and processed by means of melting. Melted and recrystallized basalt has demonstrated promising behavior with regards of its use in manufacturing, as reported in the literature. This work aims to present some aspects regarding the opportunity of using basalt in manufacturing the subassemblies of machine-tools. The research was made using grey cast iron and steel parts as reference for a comparative study. The researches presented in this work were focused on analyzing the behavior of basalt parts submitted to static stress. Testing methodology, specific measuring apparatus used, experimental test data records, data processing and resulting conclusions are presented in the paper.

Balkan Region Conference on Engineering and Business Education, 2014

Kanban is often seen as a central element of Lean manufacturing and perhaps is the most used prod... more Kanban is often seen as a central element of Lean manufacturing and perhaps is the most used product application system. Kanban is the essence of the concept that a supplier or a products deposit must distribute the components in place and at the time the production needs them so that there are no stocks in the production area. The implementation of the Kanban concept must go through four different stages; each of these stages having more steps to be followed. The paper shows some analysis elements regarding the degree of knowledge and practicability in the study of the management of the Kanban systems implementation to be followed by students in technological practice.

Applied Mechanics and Materials, 2015

In the construction of high performance mechanical transmission with high precision in movement a... more In the construction of high performance mechanical transmission with high precision in movement and positioning are used ball screws with preloaded double nuts. Among the factors that influence the performance of these transmissions are friction idle torque and friction load torque. Because, theoretically, the friction idle torque is influenced only by the preload force that loading, the double nut of the ball screw, was experimentally determined dependence of that torque of screw speed. Given the set was determined and exposed in the present work, the relation of dependency, idle friction torque, preload force and screw speed. From the relationship thus obtained can determine the instantaneous friction coefficient of the ball screw, a value that is found in the expression of power lost through friction - default transmission efficiency.

This article explores the process of calibrating the properties of DC01 materials for finite elem... more This article explores the process of calibrating the properties of DC01 materials for finite element analysis using ABAQUS and Isight. Precise calibration of yield strength and tensile strength is crucial for accurately modeling material behavior under various loading conditions. The article details the sample preparation process, deformation measurements, and tensile tests to obtain experimental data. These data are then used to calibrate the DC01 material model in ABAQUS with the assistance of Isight, ensuring that the simulations accurately reflect realworld behavior. The results indicate the success of the calibration, facilitating the design and testing of products in a predictive virtual environment. Precise calibration is essential for predicting material behavior in real-world conditions and minimizing the risk of implementation failures.

This paper presents the results of some experimental tests concerning the basalt parts submitted ... more This paper presents the results of some experimental tests concerning the basalt parts submitted to specific thermic stresses, and resulted from the operation of machine tools. The tests were also involved in similar cast iron parts, in order to compare the results and to establish the possibility of using basalt in building mechine tools.

Annals of the Oradea University: Fascicle Management and Technological Engineering, 2011

The paper describes an interactive decision support framework designed to aid decision makers in ... more The paper describes an interactive decision support framework designed to aid decision makers in selecting the most appropriate machines for a flexible manufacturing system (FMS). The framework can be used in the prescreening stage of the planning process, after a decision has been made, in principle, to build an FMS. The framework mainly consists of two parts. The first part (this paper) is called the prescreening stage, which narrows down all possible configurations by using the analytic hierarchy process..

Applied Mechanics and Materials, Jun 1, 2016

After the first time invention of Kanban system by Ohno Taiichi [1], Kanban system is becoming mo... more After the first time invention of Kanban system by Ohno Taiichi [1], Kanban system is becoming more and more famous in industries and nevertheless its importance and implementation is increasing faster than ever before. Main objective is to address this question thoroughly, how knowledge base Kanban system can be useful in future. This research work shows a modeling approach of Kanban system implementation to improve and meet the requirement of knowledge by implementing Kanban system using just in time concept given by Ohno Taiichi for academic institution. It also describe how can this system be implemented and how can we benefit from this system in a different way. Its advantages and disadvantages are also discussed this paper.

Applied Mechanics and Materials, May 1, 2015

The objective of this paper is the design of some elements of equipment for the closing of shock ... more The objective of this paper is the design of some elements of equipment for the closing of shock absorbers through the rolling method with a wide range of tank tube lengths and also of the functional structure of the equipment with the shifting/settlement of the damper in the sertization process. Closing damper device is intended by the deflection of the upper reservoir tube. In the paper, the author present his concerns regarding the study and design (parts CAD, the crimping devices) of this equipment which use this proposed technology [1, 2] for the crimping rolling method for shock absorbers reservoir cylinders.

MATEC Web of Conferences

Although research on incremental forming process began a few decades ago, it is still a process i... more Although research on incremental forming process began a few decades ago, it is still a process in development phase. Single point incremental forming is a simple process and the deformation of the sheet blank is done with the help of a punch that follows a known toolpath. In the case of this process, one important aspect is the prediction of material failure. To achieve this with the help of a finite element analysis, a series of experiments were performed to determine the forming limit diagram. In this paper, an attempt has been made to determine the forming limit diagram for the AA1050 aluminum alloy. The experiments were performed with the help of an industrial robot, KUKA KR 210-2, thus the part can be measured with an optical measuring instrument obtaining the major and minor strain from forming limit diagram.

MATEC Web of Conferences, 2019

Single point incremental forming is a process which is primarily used for prototyping, small seri... more Single point incremental forming is a process which is primarily used for prototyping, small series production and unique parts. This procedure shows a high potential in the development of complex shape parts where the time of the execution does not play an important role. Among the applications of this process are the execution of various medical prostheses, such as: knee prostheses and cranial implants. The aim of this paper is to determine the forces which take place during the manufacture process of an cranial implant, as well as the thinning of the material through the help of finite element analysis. After the numerical simulation, from the results obtained it is possible to observe the behaviour of the material at different forces which appear during the deformation process. In addition, in this paper will be presented considerations about the thinning of the material used for the cranial implant.

The Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science, 2020

Basalt is a material available in big quantities in nature. It has a low price and can be used in... more Basalt is a material available in big quantities in nature. It has a low price and can be used in various domains. It can be relatively easily extracted from natural deposits and processed by means of melting. Melted and recrystallized basalt has demonstrated promising behavior with regards of its use in manufacturing, as reported in the literature. This paper presents the results of an experimental study on the determination of the modulus of elasticity of molten and recrystallized basalt by the method of resistive electrical tensometry and to validate the result and by simulation using finite elements method. Testing methodology, experimental test, data records, data processing and resulting conclusions are presented in the paper.

This paper presents some aspects of diagnosis bearings in preventive maintenance and the importan... more This paper presents some aspects of diagnosis bearings in preventive maintenance and the importance of bearing repair as an alternative to replacing them. Bearing repair is not a new concept, nor has it changed a great deal over the years. Repairing damaged bearings is a precise science that has been fine-tuned over time through careful and gradual enhancements to provide superior results. Knowing and understanding the value of bearing repair means knowing what repair can do, when to use it, and where to get it done.

Acta Universitatis Cibiniensis. Technical Series

Nowadays, there is a high demand for rapid prototyping parts and for products manufactured throug... more Nowadays, there is a high demand for rapid prototyping parts and for products manufactured through plastic cold deformation. Incremental forming process is one of many which presents numerous advantages for fast production of complex shape parts. The purpose of this study is to develop a numerical model through finite element analysis to simulate the incremental forming process. For this analysis a variable wall angle part (VWA) which ranges from a 45° wall angle at the higher base of frustrum cone to a 70° wall angle at the base of the shape was proposed. The numerical model showed where the maximum strains are localized, how big the forces are during the process and how much the material thinned. Although the model does not indicate a possible failure of the material, the integrity of the structural stiffness was altered due to a minimum thickness reached of just 0.26mm.

Acta Universitatis Cibiniensis. Technical Series

In general, a large part of the time is devoted to the design and production of reliable parts wh... more In general, a large part of the time is devoted to the design and production of reliable parts where extensive knowledge is required for the design engineers to come up with an optimal solution for the tooling and sheet metal forming processes. Most of the time, the principle of trial and error is used to get the desired shapes for the products. This is because the prediction of deformations occurring in sheet metal elements is not available and is highly dependent on the geometry of the part, the tools and the deformation process. Prediction is limited by the proper location of necking, shear breakage, and puckering of the material. Searching for a robust deformation process by trial and error is expensive and inefficient. The use of numerical simulations provides engineers with an alternative efficiency for developing a tool and process to produce quality parts in a more efficient and lower cost. Computer simulation is an extension of theoretical science that is based on mathemati...

This paper present some researches concerning the stability in use of cold-working machines drive... more This paper present some researches concerning the stability in use of cold-working machines driven with electro-hydraulic servo-systems such as hydraulic linear amplifiers. In this work, a complex synthesis of electro-hydraulic servo-systems used in driving machines and industrial robots is also presented. The researches conducted upon a particular system, reveal the optimum design elements for obtaining a good behaviour in use, subsequently a good stability in use.

In this paper it is described a generic system architecture for increasing the flexibility of man... more In this paper it is described a generic system architecture for increasing the flexibility of manufacturing systems; there is also briefly explained how to configure the different resource modules that actually control the tasks of the physical device and put together a work cell consisting of other FMS resources. Using the principles of distributed object technology there could be implemented each resource in the work cell as a distributed object. A resource, modelled as a distributed object, has a well-defined interface, describing the data and the methods that it supports. A distributed object can execute either on the same computer or another networked computer. Finally, an example on building a FMS using a hierarchical approach is presented.

This paper presents the main CAD – computer aided design – elements of an automatic transfer syst... more This paper presents the main CAD – computer aided design – elements of an automatic transfer system, air-driven, destined for some charging/disposal operation of some work posts for the assembly/testing of the subsystem-carcass, in agreement with Compa SA Sibiu. The carcass, the manipulated subsystem, is part of the turbocompressor assembly (compressor + turbine) – of a testing equipment. The analyzed manipulator for the handling of 7 work posts, with direct application to the charging with disc type subsystems from subsystem palletainers, can be generalized to the serving, to the purpose of testing, of many such posts in a automatised assembly line and carcass checking.

The present research refers to the analysis and the synthesis of an electro-hydraulic servosystem... more The present research refers to the analysis and the synthesis of an electro-hydraulic servosystem, specific to heavy machine tools. It is presented the construction and the functionality of the servosystem, the physical elements of design and its mathematical modelling, the correspondent transfer function and the results of the research, with the afferent restrictions.

MATEC Web of Conferences, 2021

The aim of this paper was to carry out a theoretical (numerical) scientific research on the behav... more The aim of this paper was to carry out a theoretical (numerical) scientific research on the behavior of cast and recrystallized basalt, in order to use it as a material in the manufacture of structural elements of machine tools. A unitary methodology has been established for studying the eigenfrequency of structural elements for machine tools by the finite element method. Two basalt structural elements (beam type and plate type) were modeled, which were also made physically, and with the help of the COSMOS / Mark finite element program, the eigenfrequencies of the models was studied.

ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2014

The paper presents aspects regarding the development of a mobile robot (on wheels) fitted with AT... more The paper presents aspects regarding the development of a mobile robot (on wheels) fitted with ATmega328P-PV microcontroller and infrared and ultrasound sensors for detection. The robot programming elements and the test of its characteristics and performance are also highlighted. The robot is able to pursue an autonomously route determined in advance and avoid any obstacles which might arise in its path, returning then to the default route.

MATEC Web of Conferences, 2017

Basalt is a material available in big quantities in nature. It has a low price and can be used in... more Basalt is a material available in big quantities in nature. It has a low price and can be used in various domains. It can be relatively easily extracted from natural deposits and processed by means of melting. Melted and recrystallized basalt has demonstrated promising behavior with regards of its use in manufacturing, as reported in the literature. This work aims to present some aspects regarding the opportunity of using basalt in manufacturing the subassemblies of machine-tools. The research was made using grey cast iron and steel parts as reference for a comparative study. The researches presented in this work were focused on analyzing the behavior of basalt parts submitted to static stress. Testing methodology, specific measuring apparatus used, experimental test data records, data processing and resulting conclusions are presented in the paper.

Balkan Region Conference on Engineering and Business Education, 2014

Kanban is often seen as a central element of Lean manufacturing and perhaps is the most used prod... more Kanban is often seen as a central element of Lean manufacturing and perhaps is the most used product application system. Kanban is the essence of the concept that a supplier or a products deposit must distribute the components in place and at the time the production needs them so that there are no stocks in the production area. The implementation of the Kanban concept must go through four different stages; each of these stages having more steps to be followed. The paper shows some analysis elements regarding the degree of knowledge and practicability in the study of the management of the Kanban systems implementation to be followed by students in technological practice.

Applied Mechanics and Materials, 2015

In the construction of high performance mechanical transmission with high precision in movement a... more In the construction of high performance mechanical transmission with high precision in movement and positioning are used ball screws with preloaded double nuts. Among the factors that influence the performance of these transmissions are friction idle torque and friction load torque. Because, theoretically, the friction idle torque is influenced only by the preload force that loading, the double nut of the ball screw, was experimentally determined dependence of that torque of screw speed. Given the set was determined and exposed in the present work, the relation of dependency, idle friction torque, preload force and screw speed. From the relationship thus obtained can determine the instantaneous friction coefficient of the ball screw, a value that is found in the expression of power lost through friction - default transmission efficiency.