bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of the Taguchi Optimization Method in Order to Improve the Quality of the Conical Mini-Parts Obtained by Forming Process
Authors: Teaca Robert Stefanut , Brabie Gheorghe
Published: October 2014

Micro and mini manufacturing is becoming more important than before. Among micro and mini manufacturing processes, micro forming has economical and ecological benefits due to high production rate, low material scrap rate, net shape production, and improved mechanical properties through work hardening. Even though macro scale metal forming is well understood and has been extensively studied, these concepts cannot be applied directly to the micro scale metal forming [. In this paper, a conical mini-part was precisely evaluated from finite element (FE) simulation. The final geometry of the conical mini-part is affected by forming parameters of the deep drawing process (blankholder force, friction coefficient, speed of the deformation tools) and by the tool geometry. In order to reduce the geometry deviation, all the parameters must be studies separately to quantify their influence on the final mini-part geometry. This paper presents a study concerning the optimization of the forming process in order minimize the geometry deviation of the final parts. The main objective is to understand the factors that have the highest influence on the forming process of conical mini-parts and to modify them in such way that the resulted part is according to the designer specifications. The material used in this analysis is copper - zinc alloy with anisotropic properties. After the forming process of conical mini-parts is over and the part is removed from the forming tools, the geometry of the part is analysed and compared with the ideal shape. Due to cumulated effect of springback and other phenomena that affect the conical mini-part is not having the desired accuracy from the dimensional deviation point of view [2,. There are multiple factors that affect the mini-part geometry during forming process as: blankholder force, punch rounding radius, and side wall angle. The Dynaform 5.9.1 software was used to simulate the forming process. During optimisation process 27 simulations have been done. The part obtained after each simulation is analyzed and measured to quantify the deviation from the ideal part geometry. The presented optimization method is a good method to reduce the dimensional deviations. The advantages of this method are the reduced number of simulations tests that must be done and precision of the obtained results.
Contributions Regarding Incremental Forming Process of Bimetallic Sheets
Authors: Tera Melania , Bologa Octavian , Breaz Radu Eugen , Racz Sever Gabriel
Published: October 2014

Incremental forming is a process with a high degree of novelty, so this paper describes first of all a series of theoretical principles of the incremental forming process. A main objective of the paper was the usage, as blanks in incremental forming process of bimetallic sheets. So the experimental researches have targeted the realising of parts with different shapes made from such type of blank. In the experimental researches was chosen as technological equipment for incremental forming the numerical controlled milling centre. The paper also present the tools used in incremental forming in order to obtain a hemispherical parts.
Study on Process Parameters in Fiber Laser Micro-Cutting Technology
Authors: Iliescu Mihaiela , Necşoiu Teodor , Stanciu Elena Manuela
Published: October 2014

Sections: Fiber laser is a widely used “tool” for micro-machining various materials, in high accuracy condition. Still, there are not set rules and / or principles, so that to be sure of obtaining the required geometric precision for the part. This paper presents some attempts for setting procedures and parameters values domains, so that to further develop technologies for fiber laser micro-drilling of stainless steel sheets, with thickness of 0.5 mm.
Experimental Investigation on AECM of High Speed Steel
Authors: Ungureanu Cătălin , Ibănescu Radu
Published: October 2014

Abrasive electrochemical machining (AECM) is a complex technological method used for machining hard materials. This method is based on a combination of mechanic, electric and chemical factors. Present paper presents the results of experimental researches accomplished by authors in order to determine the influence of main working parameters (such as voltage, abrasive wheel speed, longitudinal feeding rate, contact pressure) upon performances of electrochemical grinding (total amount of removed material, roughness of machined surfaces, radius of edge roundness) of high speed steel.
Optimization of Reactive Sputtering Technology for Hard Coatings Deposition
Authors: Strnad Gabriela , Jakab-Farkas Laszlo , Papp Sandor , Fekete Albert Zsombor , Biro Dominic , Vida-Simiti Ioan
Published: October 2014

The paper presents the research work carried out in order to optimize the technology and reactive magnetron sputtering system used for the deposition of hard, multielemental, multiphase coatings. On the basis of a model of dynamic pressure developed and validated by us, regulatory structures for dynamic pressure inside the deposition chamber were designed and implemented. By using this optimization, extensive experiments involving nanostructured (Ti, Al, Si)N coatings, with a thickness of approx. 2 μm, were carried out. Using TEM microscopy, SAED and Vickers microhardness characterizations the results of deposition system optimization on the microstructure and microhardness of thin films were investigated.
Determining the Coefficients of Fusion and of Weld Deposition at Mechanized Mag-C Welding with Solid Wire and Cored Wires
Authors: Mihăilescu Dănuţ , Gheonea Marius Cornel , Georgescu Bogdan
Published: October 2014

In the case of the MAG welding of carbon and low-alloyed steels wires or hollow wires with (rutilic or basic) flux with metallic powder or self-protection are used. In indoors weldings huge quantities of smoke, gases, dust and particles in suspension, etc. get accumulated. These noxious substances produced during the welding process may severely affect the welders health. To improve the welders working conditions, on an international scale, the following are used: welding masks with self-obscurazation and air control; noxious substances vacuum cleaners fitted with filters; MAG welding pistols with gase and smoke absorbing devices. For the improvement of the welders working conditions, producers of welding materials invented hollow wires with (rutilic flux or with metallic powder) with a smoke-reduced emission [1,2,3,4,5].
Experimental Investigations on Aluminium Ultrasonic Welding Parameters
Authors: Apetrei Lăcrămioara , Rață Vasile , Rață Ruxandra , Bulai Elena Raluca
Published: October 2014

Research evolution timely tendencies, in the nonconventional technologies field, are: manufacture conditions optimization and complex equipments design. The increasing of ultrasonic machining use, in various technologies is due to the expanding need of a wide range materials and high quality manufacture standards in many activity fields. This paper present a experimental study made in order to analyze the welded zone material structure and welding quality. The effects of aluminium ultrasonic welding parameters such as relative energy, machining time, amplitude and working force were compared through traction tests values and microstructural analysis. Microhardness tests were, also, made in five different points, two in the base material and three in the welded zone, on each welded aluminium sample. The aluminum welding experiments were made at the National Research and Development Institute for Welding and Material Testing (ISIM) Timişoara. The ultrasonic welding temperature is lower than the aluminium melting temperature, that's so our experiments reveal that the aluminium ultrasonic welding process doesn't determine the appearance of moulding structure. In the joint we have only crystalline grains deformation, phase transformation and aluminium diffusion.
Investigation of the Electro-Discharge Open-Hole Machining on the Structural Behavior of Carbon Fiber Reinforced Polymers
Authors: Korlos Apostolos , Tzetzis Dimitrios , Mansour Gabriel
Published: October 2014

The current work investigates the electro-discharge machining (EDM) of plain woven carbon reinforced polymer composites with pulse durations of 100 μs, 200 μs, 300 μs, currents 1 A, 3 A and 5 A, and a voltage of 100 V. An x-ray computed tomography (CT) is employed to examine the delaminations, while a delamination factor model utilizing the equivalent delamination diameter provides the measuring quantity for assessment. Finite element simulations compute the stress concentrations around the holes by taking into account the delamination equivalent diameters of the open-holes, as monitored from the x-ray CT. The Whitney-Nuismer point stress criterion is utilised in order to predict the failure strength of the machined open-hole laminates and it is compared with the experimentally derived mechanical strength values. The results reveal that EDM is a feasible method for open-hole machining of composites, however proper selection of the operational parameters is needed. By accurately measuring the peripheral delamination areas of the machined holes, it is shown that the analysis of the mechanical behaviour of the plain woven laminates by the means of finite element method and the Whitney-Nuismer criterion can accurately predict the response of such composites when subjected to tensile loads.
Using Delmia V5 for Human Activity Improvement in an Assembly Line Production
Authors: Ghinea Rares Adrian , Popescu Daniela , Neamțu Călin , Hurgoiu Dan , Popister Florin
Published: October 2014

This paper presents a methodology for the simulation and optimization in a virtual environment of a manual assembly process. For validation of the methodology the authors chose an assembly process that is already used in the manufacturing industry. In the first step of the proposed methodology the existing process is simulated and then based on the simulation the activities and equipment involved are being analyzed and in the next step the assembly process is to be optimized using simulation and a series of modification vectors such as: layout, devices, tools and movement sequences. The case study presented in the paper aims to optimize the assembly process of a pneumatic actuator of a butterfly type valve.
Experimental Studies Regarding the Mechanical Behaviour of Silicon-Coated and Uncoated P.A. 6.6 Fabrics
Authors: Oleksik Mihaela , Oleksik Valentin
Published: October 2014

These paper aims to present an experimental study for determining the mechanical properties of woven fabrics used for airbags manufacturing. In order to realise the study, there were chosen two types of fabric, one that is coated with silicon and one that is uncoated. The experimental tests that were carried out were uniaxial tension tests for samples extracted on the warp and on the weft direction, the Bias test, a test specific for shear loads and the dome test, a test specific for biaxial loads. For the uniaxial tension test the force-displacement curve was obtained and the maximum values of the loads and the displacement. For the last two tests (bias test and dome test) there have been determined the maximum load, the displacement at maximum load, but also the local major strains obtained. All tests were carried out on a tensile and compression testing machine Instron 5587, while for measuring the main strains there has been used also the optical measuring system Aramis.
NiTi Shape Memory Alloy Active Element Behavior in Long Time Solicitation Conditions
Authors: Ursanu Dragoş Adela , Stanciu Sergiu , Cimpoeşu Ramona , Adoroaie Cristian George , Paraschiv Petronela , Bernevig Mihai
Published: October 2014

Equi-qtomic NiTi (nitinol) shape memory alloy (SMA) is a good potential candidate material for use as thermo-mechanical actuator in a large variety of engineering like automotive and aerospace applications. Shape memory alloy in action are required to perform a large number of actuation cycles under cyclic thermo-mechanical loads and therefor are subject of fatigue. A shape memory alloy, supplied from Nimesis Technology, with martensite to austenite temperature transformation domain 76-80 °C. The material characteristics were investigated through differential calorimetry (DSC) before and after the thermo-mechanical solicitations. Under Joule effect and a timer, the active element goes up to 3000 cycles with a 500g weight on. The properties of thermo-elastic martensite transformation are the elastic accommodation of volume and shape change that takes place due to change in crystal structure upon phase transformation. A modification of the first coil of the intelligent arch-wire suffer a modification of the temperature transformation domain increasing the As and Af temperature values.
Implementation of Shape Memory Alloys as Active Elements in Injuries Recuperative Equipment
Authors: Ursanu Dragoş Adela , Stanciu Sergiu , Cimpoeşu Nicanor , Dumitru Mihai , Paraschiv Ciprian
Published: October 2014

Entire or partial loss of function in the shoulder, elbow or wrist represent an increasingly common ailment connected to a wide range of injuries or other conditions including sports, occupational, spinal cord injuries or strokes. A general treatment of these problems relies on physiotherapy procedures. An increasing number of metallic materials are continuously being developed to expect the requirements for different engineering applications including biomedical field. Few constructive models that can involve intelligent materials are analyzed to establish the advantages in usage of shape memory elements mechanical implementation. The shape memory effect, superelasticity and damping capacity are unique characteristics at metallic alloys which demand careful consideration in both design and manufacturing processes. The actual rehabilitation systems can be improved using smart elements in motorized equipments like robotic systems. Shape memory alloys, especially NiTi (nitinol), represent a very good alternative for actuation in equipments with moving dispositive based on very good actuation properties, low mass, small size, safety and user friendliness. In this article the actuation and the force characteristics were analyzed to investigate a relationship between the bending angle and the actuation real value.
Dynamic Diagnosis of Elastic Coupling Transmissions of Technological Equipments Based on Joint Time-Frequency Evaluations
Authors: Năstac Silviu , Debeleac Carmen , Simionescu Cristian
Published: October 2014

This work presents a practical solution intended for dynamic diagnosis of the technical systems based on a set of computational methods for processing and analyzing of the acquired signals. This ensemble of methods leads to the joint time-frequency evaluations and assures a multiple way to estimate the potential damages of certain parts of the tested system. Short-Time-Fourier-Transformation, Cepstrum analysis, power spectral density estimate, together with a group of stochastic estimators composes the structured procedure for dynamic diagnosis. The proposed approach of dynamic diagnosis combines the advantages of the time domain analysis, such as the simplicity and the possibility of parameters investigation during their time evolution, with the power of spectral complex evaluations, sustained by the distribution and shifting trend of spectrum. Hereby it has provided a suitable tool for characterization of spectral composition changes in time during the entire experimental tests. This information is able to reveal the dynamic behaviour changes of supervised parts, components or entire system.
Considerations Regarding the Functionality of Chuck Collets in Mechanical Systems
Authors: Rață Vasile , Apetrei Lăcrămioara , Rață Ruxandra
Published: October 2014

In this paper the authors present the construction of a modular processing device, fitted by collet mechanisms. A research study of the operation indicators and its specific performance were made for the designed device. In this study the axial errors were eliminated by using a mobile supporting disc, front supported on the collet mechanisms housing, possibly on main shaft. The functionality conditions of the collet mechanisms were established taking into consideration the force transmission ratio and the mechanism efficiency.
Geometric Aspects and Particularities in the Functioning of a Reductor with Balls
Authors: Dohotaru Ion , Casian Maxim
Published: October 2014

Benefits of mechanism with balls are to promote their interests in different aspects in different fields of modern technology. May be remarked considerable success in screws with balls, guides, couplings etc. Are in the ascendancy searches for optimal solutions in speed-reducers with balls. One of the possible contributions to the research for technical solutions in this area is presented below. It shows the geometric particularities and configuration of a spherical ball transmission, constructive modeling and simulation of function. On an outside spherical surface of one wheel there is a sine wave path ball race. The second wheel has on an internal surface longitudinal inclined channels in which the balls are located.
Looking for a Mathematical Solution for a Self-Centering Device
Authors: Pămîntaş Eugen , Banciu Felicia Veronica
Published: October 2014

Proper centering problem is common to processing by cutting the metal or nonmetallic cylindrical parts. This paper proposes a solution useful in self-centering devices with mobile jaws, both in terms of cinematic jaw movement - rotation instead of translation - as well as the active profile of the jaw - curvilinear instead of straight. The method of problem solving is mathematical deduction, on the one hand by establishing the geometrical calculus schemes that describes the graphic curves for the envelope of a single-sided curvilinear profile for jaw, and on the other by the generalization of the solution for the case the active surfaces of the jaws are both curvilinear profile.
Experimental Research Regarding Static Rigidity in Axial Direction of "Narrow" Modules from Modular Fixtures Structure
Authors: Chitariu Dragoș Florin
Published: October 2014

In the paper a research methodology was developed and used to determine the rigidity in the axial direction.The paper presents a the experimental results regarding the total deformation of narrow modules found in the structure of modular sets. The research conducted showed the different evolution of deformation curves in the case of modular structure composed of modules, with different shape and different sizes, in the case of similar loads
Influence of Guideways Misalignment on the Positioning Precision of Kinematic Feed Chains Used on CNC Machine Tools
Authors: Funaru Marian , Stan Gheorghe
Published: October 2014

The main goal of the kinematic feed chains used on numerically controlled machine tools is to ensure the relative position between the manufactured part and the cutting tool tip with a high accuracy. Therefore, the positioning precision is a major performance criterion for CNC machine tools. The guidance system of the machine table, together with the actuation system and the closed-loop control system, represents a key factor in manufacturing high precision machine tools. Mounting and alignment errors of guideways, both in vertical and horizontal directions, directly affect the table positioning precision and implicitly, the manufacturing precision of the machine tool. Guideways misalignment also generates stresses, plays and excessive run-out. The present paper contains a method of experimental analysis regarding the influence of guideways alignment errors on the positioning precision of the kinematic feed chains, which takes into account the alignment of the two guide rails, both in vertical and horizontal plans. The feed axis used in the experimental setup is closed-loop controlled, making use of an indirect position measurement system.
Research Regarding Improvement of Dynamic Behaviour for High-Ratio Planetary Gears
Authors: Butunoi Paul Alin , Stan Gheorghe , Ciofu Catalina
Published: October 2014

High-ratio planetary gears are frequently used in robot arm articulations for the purpose of transmitting motion from the electric motors to the moving elements. Actual planetary gears used in industrial robots have a relatively large weight related to the gear ratio, which leads to a high inertia of the moving elements.Throughout this paper, a novel computation method of the dynamic momentum is presented as well as constructive methods used to improve the dynamic behaviour of the planetary gear. The optimization method regarding the dynamic behaviour is based on the reduction of all moving masses towards the motor shaft but also on new construction strategies for planetary gears that help minimizing the gyration momentum. This method has been applied for a three-stage planetary gear having a gear ratio of 175,61:1 in order to optimize the shape of the carriers that are attached to the output shafts, according to its kinematic diagram. The results obtained will be presented comparatively and in a graphical form, thus serving as a practical guide addressed to the designers or manufacturers of industrial robots.
Aspects Concerning the Possibility to Measure the Radial Deflection of a Work Piece Obtained into a Turning Process
Authors: Boca Mihai , Nagîț Gheorghe , Horodincă Mihăiţă , Negoescu Florin , Mihalache Andrei Marius , Rȋpanu Marius Ionuţ
Published: October 2014

In the technical literature there are some studies which use measured signals in order to compensate the errors caused by vibrations [1, 2], by the cutting force [3], by the deflections of the technological system [4], and others. Also, the technical literature presents some studies [6, which give few measurement techniques in order to measure the error which appears into the turning process and also, some methods to compensate or eliminate the consequences produced by those errors. In such conditions, this study propose to establish a possible methodology that can make the measurement of the radial deviation which corresponds to a work piece obtained into a turning process. The novelty of this study comes from the method of measurement used and from the measurement stand which provide the values of the radial deflection for the processed work piece, during the process. The experimental procedure assumes the existence of an experimental stand which allows to measure the distance between a sensor and the considered work piece. In such conditions, the mathematical algorithms used will transform the received electrical signal into a physical displacement. The obtained results suggest that the signal provided by the experimental stand and which it is used for measure the distance between a sensor and the considered work piece, allows to establish, with accuracy, the values for the radial deviations of the work piece. Also, this fact can offer a graphical representation of the shape which corresponds to the real profile of the processed work piece.
The Method for Determining the Vibration-Damping Elements for the Mechanical System to Obtain the Desired Amplitude Value
Authors: Dymarek Andrzej , Dzitkowski Tomasz
Published: October 2014

The paper presents the use of synthesis methods to determine the parameters of passive vibration reduction in mechanical systems. Passive vibration reduction in a system is enabled by units called dampers whose values are determined on the basis of the method formulated and formalized by the authors. The essence of the method are, established at the beginning of a task, dynamic characteristics in the form of the resonance and anti-resonance frequencies, and amplitudes of displacement, velocity or acceleration of vibration.
Dynamical Charactersitics of the Discrete – Continuous Mechatronic System Obtained by Means of Exact and Approximate Methods
Authors: Buchacz Andrzej
Published: October 2014

The research of subsystems establishes the foundation to complex systems analysis with cascade structure. Analysing the diagrams of characteristics of confirmed system it has been determined that in case of approximate method the resonance frequencies cover with those which have been determined with exact method. However the values of the characteristic in other areas are different. The main aim of the paper is to study the dynamic characteristic of the discrete continuous mechatronic system determined by exact approximate, that means Galerkin's method for torsionally vibrating complex mechanical subsystems. The system composed from many subsystems having the same length and variable cross section, loaded by the focused moment was analysed. The main subject of deliberation was to determine the flexibility of the mechanic system with constant cross section using the exact and approximate Galerkin's method. Next the method comparison and the correction of approximate method where made. As far as the mechatronic system flexibility determinations concerned the Galerkin's method has been chosen. The analysis of subsystems of mechatronic and mechanic complex systems is however the introduction to the synthesis of torsionally vibrating mechatronic systems with assumed frequency spectrum.
Researches Regarding the Influence of Temperature on a Weigh-in-Motion Hydraulic System
Authors: Mardare Irina , Tiţa Irina
Published: October 2014

Weighing in motion systems, regardless the type of sensor that a system utilizes is working in difficult conditions: dust, slag, layer of ice or snow, high humidity, varying temperatures during a day, or a year [. All these conditions influence the accuracy measures of the work done and require the correction factors application.In this paper it presents the analysis of the temperature influence on a new type of weighing in motion sensor, namely hydraulic sensor. Is presented the simulation scheme designed to simulate the experimental model used in the laboratory and the results obtained through simulation, on the temperature influence on the experimental model tested.
Method for Redesign of District Heating Networks within Transition from the 2nd to the 3rd Generation
Authors: Lefter Răzvan Corneliu , Popescu Daniela , Untăroiu Alexandrina
Published: October 2014

Important investmentsare made lately in the area of district heating, as a technology capable ofhelping countries to reach sustainability goals. In Romania, European fundswere spent for transition from the 2nd to the 3rdgeneration of district heating systems. The lack of appropriate monitoringsystems in old district heating systems makes optimisation nowadays very difficult,especially because nominal values used in the first design stage areoverestimated. Realistic nominal heat loads are necessary to make goodestimations of hydraulic parameters to be used for redesign. This studyproposes a method that uses the heat load duration curve theory to identify theappropriate nominal heat loads to be used for redesign. Comparison betweenresults obtained by applying the nominal heat loads of each consumer, as theywere established in the first design stage, and the ones identified by theproposed method are analyzed in a case study. The results show that errors arein the +/- 3% band, between the metered heat consumption rates and the proposedrates. The new method can be used for the sizing of pumps and district heatingnetworks after retrofit, in order to get better adjustments of the circulationpumps and increase of the energy efficiency.
Using Parameter Deviation Function for Estimating the Calibration Life of Micrometers
Authors: Clinciu Ramona
Published: October 2014

The paper presents the results of an experimental study performed on specific measuring devices micrometers, study aimed at determining the calibration life of these measuring devices as a function of the metrological reliability, due to the internal parameter deviation. The experimental study conducted is aimed at determining the calibration life of external micrometers for 0 - 25 mm. The experimental data is obtained in the laboratory conditions and it is represented by the measuring errors, obtained for the same nominal size, experimental data being grouped in samples produced at a certain interval of time, by measuring the same dimension with a set of micrometers.The research performed on the considered set of micrometers can lead to the conclusion that the appropriate moment for performing the calibration for a specific set of measuring devices can be estimated by determining the calibration life based on parameter deviation functions, these being obtained by means of regression analysis. The algorithm for estimation of the calibration life of the measuring devices as a function of the metrological reliability can be used for determining the calibration life of the analysed measuring devices, such as to compare the estimated calibration life with the requirements set in the appropriate standards. In the case of the set of micrometers analysed, the pre-set calibration life proved to be earlier than necessary and the estimation of the calibration life by means of parameter deviation would reduce the total costs of the appropriate operation.
On the Right Parameterization of 3D Models - Case Study
Authors: Lambrescu Ionuţ , Pană Ion
Published: October 2014

All students in mechanical engineering courses receive training in using at least one parametric and associative 3D modeler. From the point of view of the logic behind the geometric design, a very important issue is how to parameterize the model, or put in other words, how to achieve the right balance between dimensions, as independent parameters, formulas (linking dimensions) and geometric constraints (parallel, concentric, horizontal etc.). We arrive following this logic to the notion of degrees of freedom of the model, as expressing the number of dimensions still free for a dynamic edit. The papers aim is to provide a case study capable to assist students in understanding how a good model could be built. The case study will be integrated in an on-line course, offered by our university as an expression of its commitment in developing e-learning applications [.The paper proposes a slightly different approach, compared with the ones presented in [2, 3, . While in the mentioned sources a graph approach is considered, our paper proposes a matrix oriented analysis, coupled with a live analysis of the model behavior. The paper also proposes different other models as good examples to be used in the teaching process.
Determination of Stressed-Deformed State of Fine Disc Tools with Inner Cutting Section under Conditions of their Pre-Stressing
Authors: Mikhaylov Aleksandr , Dolhykh Hanna , Casian Maxim
Published: October 2014

The work is dedicated to investigation of the particulars of stressed-deformed state of fine disc tool with internal cutting section under conditions of its pre-stressing. It was suggested for reduction of tools oscillations at cutting to apply pre-stressing of the tools disc by means of controlling elements. The elements, which control the elements stress allowed to eliminate self-oscillations and resonance oscillations of the tool at high-speed materials cutting. In the paper the problem of evaluation of stress and deformed state of fine disc cutting tools with application of the method of finite elements (FEM) was solved. The article also contains epures of tangential stresses inside the internal contour of disc tools. On the basis of the investigations performed the synthesis for design of the main elements of fine disc tools with inner cutting section was carried out. The performed investigation was aimed at improving of the quality and stability of cutting with fine disc tools under conditions of high-velocity cutting and in presence of a dynamic component of the cutting process, ensuring improvement in durability and productivity of the tool.
Smart Engineering Design of a V10 Engine Using Digital Prototyping Technologies
Authors: Haba Sever Alexandru , Oancea Gheorghe
Published: October 2014

This paper presents a method for designing of an engine group for motorsport automotive using the concept from the core to the periphery of the assembly. The core engine solution is an engine block with non-removable cylinder casing, 10 cylinders in V-normal at 72°, double overhead camshaft (DOHC) distribution solution. This powertrain solution is cooled with liquid in a pressurized cooling system. The method used is based in the first step on the modeling of the crankshaft assembly followed by, in the second step, the modeling the peripheral parts-engine assembly. In order to achieve the digital prototype of the engine group is used the CAD/CAM/CAE system named CATIA V5.
Impact Analysis of an Oxygen Mask Locking Panel of Aircraft Using Finite Element Modelling
Authors: Croitoru Emilian Ionut , Oancea Gheorghe
Published: October 2014

This paper presents a method of finite element modelling used for the impact analysis of a composite panel. In this research, the composite panel consists of an oxygen mask locking panel of an aircraft. This panel is loaded with one concentrated abuse loading and three uniform distributed abuse loading cases and the stress variation within the composite panel for each load case is determined. In order to assess the impact analysis on the oxygen mask panel of the aircraft, a finite element model is created using Patran as the main application for pre/post-processing and Nastran as the main processor. The paper also presents a comparison between results obtained using the same finite element modelling of the composite panel CAD model of the panel with four load cases with different material types. The results are used to determine the most capable material stresswise.
Parametric Modeling CAD-CAM of the Ankle and Pathological Related Situations
Authors: Huzu Iulia , Cofaru Nicolae Florin
Published: October 2014

It is primary object of the present study to create a 3D model of the human ankle and an axis system that will show the position the tibia and the foot on a healthy subject. Regarding this scope of the study, the first step in obtaining the 3D model of the bones is scanning. The graphic modeling software used is Catia V5 R20.
It is another object of the present study to create an axis system that will be very easy to maneuver and on which we can show different pathological situations, not only on a healthy subject, creating their assembly reference systems considering the mechanical and anatomical axes existing and creating prerequisites for the study of different possible pathological situations. For this scope, was used a triorthogonal axis system called skeleton that is defined as a system of axes Euler. This means that the angles can change the grid, in the desire to analyze different situations. In this study the focus is on the situation of varus equinus, in which the foot leg is not aligned with the tibia, as it is on a healthy subject. It was realized an important element: the incorporation of geometric and dimensional references.
The last object in this study is to determine the status of CAE, in order to study the stress and the strain.
Creating the CAD system is very important because it can be used to study the osteoarticular system, treatment strategies and related surgery.
Cad Development - User Custom Drafting Extensions
Authors: Batog Ionel
Published: October 2014

Many companies use Computer-Aided Design & Drafting (CADD) systems to create design drawings. Using CADD design as a replacement of the manual drafting method is only a fraction of its potential. The work that is done repeatedly can be in most cases performed automatically through customization. Customization of standard CAD packages can significantly increase productivity. The custom functions and programs can extend the capabilities of CAD packages to perform a wide range of drafting tasks. The paper discusses a customization strategy intended to facilitate completion of some repetitive drafting tasks in mechanical drafting process. One way to extend the capabilities of AutoCAD is by creating and using blocks. Blocks are useful for creating repeated content, such as standard components. The Dynamic Blocks feature enables user to modify blocks by adding parameters, actions, constraints that increase the versatility and power of the blocks. The paper presents two examples in creating and using dynamic blocks in order to save time and get maximum benefits of AutoCAD features. The first example shows a way to manage bolted joints drawing process by defining parameters and actions to the joint standard components. The second one presents a way to define and use a dynamic block with parametric design for radial ball bearings. The customization approach presented, developed for basic AutoCAD package, is intended for automating quite common tasks in mechanical design drafting. The major advantage of customization is the significant increase of drafting productivity.
Influence of Dimensional Deviations on the Positioning Accuracy of Robots with Delta 3 DOF Parallel Structure
Authors: Andrioaia Dragos , Stan Gheorghe , Cristea Ion
Published: October 2014

In the last years, due to the advantages presented by Delta 3 DOF parallel structure robots, they have been used in the field of high accuracy mechanical processing. In this field, it is demanded that the manufacture of components present high quality. The positioning accuracy for the parallel structure Delta 3 DOF robots can be affected by errors entered from the mechanical structure or by the control and command system. The accuracy class in which the mechanical elements are manufactured can affect the positioning accuracy within the robots with Delta 3 DOF parallel structure. In this paper, the authors study the ways in which the dimensional deviations of the kinematic elements influence the positioning accuracy. The method which is used correlates the dimensional deviations with the positioning accuracy. Therefore, the positioning accuracy of the Delta 3 DOF robots can be established within the design process.
Procedure of System Control Using Distributed Parameters through Discrete Finitisation
Authors: Şerban Sever , Şerban Doina Corina
Published: October 2014

This paper presents an original method for the synthesis command involving a controllability matrix, which is used for systems with distributed parameters, and further more for systems reduced to a finite dimensional space.
Pareto Optimality of Production Schedules in the Stage of Populations Selection of the MOIA Immune Algorithm
Authors: Paprocka Iwona , Kalinowski Krzysztof
Published: October 2014

In the paper, the problem of achieving Pareto optimal solutions set with application of the elaborated Multi Objectives Immune Algorithm is presented. The Pareto frontier provides a variety of compromise solutions for contradictive criteria to a decision maker. We propose the application of the selection based on the Pareto optimality to maintain solutions with great diversity in an immune memory. Stimulation and suppression mechanisms are used to control the diversity of generated solutions. Computer simulations are done for a job shop scheduling problem.
Machinability by Milling of Gray Cast Iron
Authors: Grămescu Traian , Cărăușu Constantin
Published: October 2014

In the laboratory of cutting machining technologies from the “Gheorghe Asachi” Technical University of Iaşi, a series of investigations on the machinability of cast iron samples having various structures were designed and developed. The aim of the research was to know and to explain the way in which various constituents of some iron castings exert influence on the degree of wear of a milling tool made of high speed steel. Within this research, mathematical empirical models were determined, in order to calculate the cutting speed v60, considered as an indicator for the evaluation of machinability. The research allowed establishing the factors able to have a major influence on tool wear phenomenon and obtaining thus a more complete image concerning the machinability of grey iron used for castings.
Elements of Quality Analysis in Metallic Materials Production
Authors: Ioana Adrian , Semenescu Augustin , Preda Cezar Florin
Published: October 2014

The paper presents the main methods of technical-economical analysis of the quality of the metallic material production. The technical - economical analysis of the electric steels quality can be processed both for the product (electric steel) and for the company (electric steelworks). Both the analysis methods for products (A) and the ones for companies (B) are presented in comparison. There are mainly presented and analyzed a specific analysis models for steels elaboration in Electric Arc Furnace (EAF). The main elements specific to the two categories of analysis methods, including mathematical models. The quality of the steels elaborated in the EAF is a very important parameter. From this point of view, there is the need of analyzing the electric steels quality in various methods, including by technical-economical ones. The technical - economical analysis of the electric steels quality can be processed both for the product (electric steel) and for the company (electric steelworks). For the technical - economical analysis for the electric steels quality, we can use two methods: methods of the analysis for the products quality (MAPQ); methods of the analysis for the companys (MACQ).
Determining the Duration of R&D Processes through Monte Carlo Simulation
Authors: Moga Monika , Calefariu Gavrilă , Smarandache Florentin , Sarbu Flavius Aurelian , Bogdan Laura
Published: October 2014

The research and development (R&D) processes influence the economic development of a company, because in an industry that is changing fast, firms must continually revise their projects and range of products. The novelty of the paper is that it focuses on determining components of cost and the duration of the R & D processes in its cost calculation procedure. The originality of this work is the use of Monte Carlo simulation to determine the average length of producing a new product.
Contributions Regarding the Utilization of Neural Networks in SME's Management
Authors: Marinescu Simona Ioana , Țîțu Mihail Aurel
Published: October 2014

Due to the fact that there isnt a clear definition of the terms neural network" and "neuronal network" [1,2], the current paper aims to establish it by a range of comparative research. With the help of some charts, based on the structure of some SMEs (Small and Medium Enterprises), the parts that define the structure of the neuron will be compared with the general structure of an organization, in order to reproduce the neuron in the structuring level of an organization and give a meaning to the term of "organizational neuron. Sometimes it is necessary to take managerial decisions under uncertainty and / or risk, so any method that gives forecasting information to the manager is welcome [3,4]. It is considered that the use of Artificial Neural Network (ANN) can be constituted (embodiments of many other methods) in an appropriate instrument for taking the correct decisions in the organizational management. As a result, a case on how to use an ANN will be presented, based on certain characteristics of a company. It aims at presenting how a biological neuron will be transposed into an artificial neuron (people or departments within the company) and its reproduction at a structure level of the organization (functions of the nucleus, axon, dendrites, and so on).
A Review of the Main Modeling Methods for Ball Nose End Milling Processes
Authors: Diciuc Vlad , Lobonțiu Mircea
Published: October 2014

The ball nose end mills are highly used for complex sculptured surfaces in 3-5 axes milling. The modeling of the cutting process using ball nose end mills is more complex than in the case of simple end mills due to the fact that the cutting speed varies continuously along the cutting edge. By tilting the cutting tool relative to the surface to be machined, the modeling is getting more complicated due to the large number of input variables. This paper presents a review of the main modeling types, underlining the specificity, the advantages and disadvantages for each type in comparison to an own research on a parametric CAD model. There are also recommendations made towards the modeling process, based on the results obtained by the authors.
Validating Algorithms and Methods Destined for Information System Design Meant for the Business Environment Using Simulated Companies
Authors: Neicu Marian Ştefan , Savii George Gustav
Published: October 2014

The paper presents a validation method of the information systems conceived for the business environment. Unlike the audit of the accounting information systems or of the established testing methods of the software, we suggest that for testing and validation of the information systems, they should be implemented and used through enterprise exercise. Through this, besides the actual check of the software we also evaluate the way in which the software applications adapt to the full running of a processing flow of the information, corresponding to some basic functions of the enterprise. In such way we obtain complete and good quality results, at low costs of the evaluation process.
Noise and Vibration Pollution Reduction to a Mineral Aggregates Station through Rim Optimization in Order to Align at EU Legislation
Authors: Zichil Valentin , Judele Adrian , Albut Aurelian , Sava Alexandre , Lozovanu Petru
Published: October 2014

The paper analyzes the pollution impact of vibration on the whole human body produced by sorting and washing stations of mineral aggregates, located near inhabited areas, in accordance with national legislation. The imposed limits are correlations between the frequency of vibration with the vibration intensity, measured in vibrars. In the same time, in the EU legislation the imposed limits are given by the daily exposure limit value (acceleration of vibration movement) standardized to an eight-hour reference, measured in m/s2. The authors present a geometrical rim optimization of a mineral aggregates station to diminish the pollution produced by vibrations, that should be taken, in order to align at European legislation. Results are presented in both ways: as maximum vibration intensity and maximum vibration acceleration. Measurements were performed at normal operating capacity of the analyzed plant, based on: direct observations in the field, the existing documentation and information supplied by the business owner.
Evaluating the Risk of Failure on Injection Pump Using Fuzzy FMEA Method
Authors: Rachieru Nicoleta , Belu Nadia , Anghel Daniel Constantin
Published: October 2014

This research is aimed at utilizing failure mode and effect analysis (FMEA) which is a reliability analysis method applicable to rotary injection pump design. In traditional FMEA, Risk Priority Number (RPN) ranking system is used to evaluate, the risk level of failures to rank failures and to prioritize actions. RPN is obtained by multiplying the scores of three risk factors like the Severity (S), Occurrence (O) and Detection (D) of each failure mode. RPN method can not emphasise the nature of the problem, which is multi-attributable and has a group of experts' opinions. Furthermore, attributes are subjective and have different importance levels. In this paper, a framework is proposed to overcome the shortcomings of the traditional method through the fuzzy set theory. Two case studies have been shown to demonstrate the methodology thus developed. It is illustrated a parallel between the results obtained by the traditional method and fuzzy logic for determining the RPNs. We expect that fuzzy FMEA model will assist FMEA team in assess and rank risks more precisely compared with risk assessment model of method.