0000000000084099
AUTHOR
Claudia Girjob
showing 16 related works from this author
Study of the Formability of Laminated Lightweight Metallic Materials
2017
The main objective of this work was to test the formability of laminated materials. Laminated materials are considered a good choice when parts with reduced weight are considered. Thus, a laminated material, aluminum - polypropylene - aluminum (Al-PP-Al), as sheet 1.2 mm and 1.4 mm thickness was used. Before processing the material by means of unconventional plastic deformation, its formability was determined by running the Nakajima test. After obtaining the forming limit curves, the material was machined by means of incremental forming.
Researches Regarding Optimizing the Accuracy of CNC Laser Cutting Machines
2015
The experimental researches presented in this paper are aimed to improve the manufacturing accuracy of a contouring machine together with an approach to eliminate the errors which lead to a less precise part after machining.In order to eliminate the errors, the machine's feed drives were tuned leading to a more precise part. In order to validate the proposed approach, the accuracy of the machine was tested before and after the tuning process.
Mechatronic Design of a Four-Wheel drive mobile robot and differential steering
2021
This paper presents, the development of an autonomous mobile robot with a four-wheel drive and differential locomotion. The mobile robot was developed in the Machines and Industrial Equipment Department from the Engineering Faculty of Sibiu. The main purpose of developing this type of mobile platform was the ability to transport different types of cargo either in industrial spaces or on rough terrain. Another important objective was that this platform could be driven in confined or tight spaces where a high degree of manoeuvrability is necessary. The great advantage of this type of mobile platform is the ability to navigate through narrow spaces due to the type of locomotion implemented. Th…
FEM Simulation of Laminated Lightweight Materials Processed through Single Point Incremental Forming
2015
The aim of present paper is to realize the FEM simulation of laminated lightweight material processed through single point incremental forming. Thus a laminated material, aluminum - polypropylene - aluminum (Al-PP-Al), as sheet 1.2 mm thickness was used. For these material the hardening curve was determinate. These values were used to describe elastic-plastic behavior of the material during single point incremental forming process simulation. Single point incremental forming process simulation aimed to assess the distribution of values and maximum and minimum strains, the material thickness of the specimen and the technological force for the two strategies for obtaining the truncated cone s…
Researches Regarding Optimising the Contouring Precision of CNC Laser Cutting Machines
2014
This paper presents some experimental researches regarding the manufacturing accuracy of a profiling machine together with an approach to eliminate the positioning and contouring errors. A mathematical model based on transfer functions is used as starting approach in order to tune the feed drives of the machine. The accuracy of the profiling machine is tested before and after the tuning process, in order to validate the proposed approach. There are unfolded both positioning tests along one axis and contouring tests on two axes.
Study of the Formability of Light Metallic Materials
2015
There is a continuing interest in using laminated materials for the production of lightweight parts, the resulting parts having the same functionality and even an increased stiffness and length of operation compared to conventional materials. The present paper aims to study the forming behavior of the laminated materials that requires the unfolding of tests to determine the tensile mechanical properties and the intrinsic properties, determining the forming limit curves by means of the Nakajima test and the analysis of the behavior at unconventional incremental forming.
Study upon the kinematic simulation of the incremental forming carried-on using a serial industrial robot
2021
Abstract Incremental forming with contact between tool-sheet metal workpiece in a single point is an unconventional process which allow the user to manufacture parts by combining the vertical movement of the tool along Z-axis and the horizontal movements of sheet metal workpiece, which are performed in XY plane. As technological equipment able to control coordinated movements on three axes, CNC machining centers and industrial serial robots with six degrees of freedom are the most suitable. The paper introduces a study regarding the use of robots as technological equipment for the process, by means of simulation. Supplementary degrees of freedom and singularities avoidance are also consider…
Experimental Research of the Formability of Lightweight Metallic Materials Used in Automotive Industry
2015
This paper aims to study the plastic deformation behaviour of lightweight metallic materials in order to reduce the total weight of the vehicles without affecting their performances. For the theoretical and experimental researches presented here, among these materials the AZ31B magnesium alloy has been chosen, a representative alloy for the magnesium-zinc-aluminium alloy system. The results of the theoretical researches, made on finite elements models, were validated by means of experimental researches consisting of tensile tests, forming limit curves determination tests and AZ31B magnesium alloy drawing, respectively.
Creating an ethernet communication between a Simatic S7-1200 PLC and Arduino Mega for an omnidirectional mobile platform and industrial equipment
2020
Abstract The degree of automation in the industry increases more and more every year, trying to reduce more and more or even eliminate the collaboration with the human operator. The basis of all automatic industrial equipment is PLCs. This paper presents a method of extending the number of inputs and outputs of a Siemens Simatic S7-1200 PLC, using an Arduino Mega development board and an Ethernet communication. Following the realization of this communication, the number of inputs and outputs will increase considerably, being able to connect various sensors used for the construction of an omnidirectional mobile platform, but also for equipment for industry. The advantages of using this commu…
Dynamic Analysis of a 7 DOF Robot Using Fuzzy Logic for Inverse Kinematics Problem
2019
Abstract In this paper, a dynamic analysis for a redundant, serial robot, with seven degrees of freedom is presented. The dynamic model of the robot is based on importing a tri-dimensional CAD model of the robot into MATLAB®, Simulink®-Simscape™-SimMechanics™. One can import complete CAD assemblies, including all masses, inertias, joints, constraints, and tri-dimensional geometries, into the model. The first step for executing a dynamic analysis is to resolve the Inverse Kinematics (IK) problem for the redundant robot. Because this type of robot has seven degrees of freedom the IK resolution implies an infinite number of solutions. So, to be able to resolve the IK for this kind of robot a F…
Study on the application of CAM techniques on CNC lathes with Y axis and driven tools
2021
Abstract CNC lathes with Y axes and driven tools are machine-tools with complex kinematic. Using CAM techniques to program these machines is a cumbersome process and could easily lead to collisions. Collisions may occur not only between tools and workpiece but also between the mobile elements of the CNC lathe. While CAM software package can identify the first type of collisions, for the second type supplementary measures must be taken. This work presents the build of a kinematic model of such a CNC lathe and how can the CAM techniques be improved by using this model.
Method for improving the contouring accuracy for CNC profiling machines at the shop floor level
2009
Computer Numerically Controlled (CNC) laser cutting machines are capable of producing high-quality precise parts. However, as cutting speeds is increased, in order to achieve higher productivity, the accuracy of the parts is affected. In order to improve the contouring accuracy of these machines, a simple straight-forward joint simulation and experimental strategy is proposed. The position controllers within the feed drives are considered the key factor in improving the dynamic behavior and consequently the contouring accuracy of a CNC laser cutting machine at the shop floor level.
Modular fastening system and tool–holder working unit for incremental forming
2019
Incremental forming can be usually unfolded either on CNC milling machine–tools or serial industrial robots. The approach proposed in this paper tackles the problem of designing a modular fastening system, which can be adapted for both above mentioned technological equipment. The fastening system of the sheet–metal workpiece is composed of a fixing plate and a retaining plate. The fixing and retaining plates will be made up of different individual elements, which can be easily repositioned to obtain different sizes of the part. Moreover, the fastening system has to be able to be positioned either horizontally (to be fitted on CNC milling machines) or vertically (to be fitted on industrial r…
Simulation approach for improving CNC milling machines accuracy for single axis motion
2010
CNC milling machines are widely used in manufacturing processes. In time, their accuracy is decreasing, which directly influences the accuracy of the manufactured parts. This research proposes a simulation-based method for improving the accuracy of the above mentioned machines, which is suitable to be applied at the shop floor level. A model of the feed drive, using a dc servomotor as actuator, is the core of the proposed approach. Matlab & Simulink based simulation diagrams were built in order to test the behavior of the system.
Modular device for determining forming limit curves – a cost effective aproach
2010
Abstract The paper presents the realising and functioning of a modular device for testing the formability of metal sheets. By using the device it is possible to realise experimentally the tests needed for drawing the forming limit curves using the Nakajima and Marciniak methods, but there can be also done researchs on deep-drawing. The results gathered from the tests were validated by numerical simulations using the finite element method. The device was designed at the Research Center for Metal Forming of the “Lucian Blaga” University of Sibiu and realised with the support of S.C. Uzina Mecanica Marsa – Sibiu
Considerations on Cutting Regime Influence of NC Laser Cutting Machine Tool on Processed Surface Quality
2015
This paper presents the study of the influence of cutting parameters on surface quality in laser cutting of metallic materials. In this paper, it is shown which of the cutting parameters have the greatest influence on the quality of the processed surfaces by measuring various roughness parameters. After the experimental research was carried out a ranking of the factors of influence on the response functions was made, also graphs of dependency to various parameters of roughness were made.