Abstract: This paper introduces some of the findings of the research made by the authors on the occasion of the manufacturing of a gantry type milling machine with displaceable table FLP 2200 CNC type. The designed balancing unit had to cope with the specific requirements of this type of machine, but it can be successfully used for other gantry type machine tools such as heavy vertical lathes and milling machines with displaceable gantry. Generally, in the case of heavy duty machine tools, the kinematic chains for feed / positioning that are working vertically must move large masses with velocities of 2−10 m/min, under high conditions of stability and accuracy. On the occasion of FLP 2200 CNC machine manufacturing, the authors have designed and made a single balancing unit. This fact was possible because the feed phases of the rams and the positioning phase of the crossrail are never overlapped and because the mechanical design met the conditions of maximum safety. Data is submitted about the necessity of balancing and the computational model of "discharge" of the feed / positioning kinematic chain when it is done hydraulically. It is presented the design of the hydraulic scheme used to balance both hydraulic rams and the crossrail. Also, simulating operation and the hydraulic diagram and the construction of this unit is presented. It is distinguished the need to use accumulators in the hydraulic circuit. Feed / positioning kinematic chains of the scenes must be driven by drive motors equipped with brakes.

Key words: heavy duty machine tools, hydraulic balancing, unloading of feed kinematic chains, positioning kinematic chain.

pp. 9-14 View full text

CYBER-PHYSICAL MANUFACTURING SYSTEMS – MANUFACTURING METROLOGY ASPECTS

Vidosav MAJSTOROVIĆ^1,*, Jelena MAČUŽIĆ², Tatjana ŠIBALIJA³, Srdjan ŽIVKOVIĆ⁴

¹⁾ Prof. Dr., University of Belgrade, Faculty of Mechanical Engineering, Belgrade, Serbia

²⁾PhD student, University of Belgrade, Faculty of Mechanical Engineering, Belgrade, Serbia

³⁾ Prof. Dr., Metropolitan University, Faculty of Information Technology, Belgrade, Serbia

⁴⁾ Dr., Chief of Metrology Lab., Military Technical Institute, Belgrade, Serbia

Abstract: Cyber-Physical Systems (CPS) are systems of collaborating computational entities which are in intensive connection with the surrounding physical world and its on-going processes, providing and using, at the same time, data-accessing and data-processing services available on the internet. Cyber-Physical Manufacturing Systems (CPMSs), relying on the newest and foreseeable further developments of computer science, information and communication technologies on the one hand, and of manufacturing science and technology, on the other hand, may lead to the 4th Industrial Revolution, frequently noted as Industry 4.0. CPMS consist of autonomous and cooperative elements and sub-systems that are getting into connection with each other in situation dependent ways, on and across all levels of production, from processes through machines up to production and logistics networks. Modeling their operation and also forecasting their emergent behavior raise a series of basic and application-oriented research tasks, not to mention the control of any level of these systems. The fundamental question is to explore the relations of autonomy, cooperation, optimization and responsiveness. Integration of analytical and simulation-based approaches can be projected to become more significant than ever. One must face the challenges of operating sensor networks, handling big bulks of data, as well as the questions of information retrieval, representation, and interpretation, with special emphasis on security aspects. Novel modes of man-machine communication are to be realized in the course of establishing CPMS. The main goals of the paper are to discuss those approaches and milestones pointing towards the realization of Cyber-Physical Manufacturing Systems as well as to highlight some future R&D opportunities, especially in manufacturing metrology area.

Key words: manufacturing, ICT, modeling, simulation, manufacturing metrology.

pp. 15-22 View full text

DYNAMIC EVALUTION OF THE VIBRATING DRILLING SYSTEM

Claudiu-Florinel BÎȘU^1,*, Jean Yves K’NEVEZ², Medhi CHERIF²

¹⁾Assoc. Prof., PhD, Machines and Manufacturing Systems Department, University "Politehnica" of Bucharest, Bucharest, Romania

²⁾ Assoc. Prof., PhD, Materials Production Interaction Department, Institute of Mechanics and Materials, Bordeaux, France

Abstract: New materials technologies have led to new composite materials solutions to replace existing conventional materials. The compliance of the quality and the life span of drilling tools becomes difficult, these two being considerable reduced. The constraints generated during the drilling process are very important in amplitude and complexity. For this purpose, an adopted machining solution based on vibration assisted drilling was presented. This paper aims to dynamic study of a new drilling solution assisted with vibration. This system is the subject of a patent. To evaluate the dynamic behaviour of the drilling vibration system an experimental setup was designed and built. The study allowed the identification of natural frequencies and determination of dynamic parameters: stiffness, damping and mass. These parameters are required in the further development of a dynamic model to optimize the reel cutting conditions. For this purpose a dynamic evaluation of drilling system assisted with forced-vibrations was imposed.

Key words: drilling, vibratory system, vibrations, dynamics, evaluation.

pp. 23-28 View full text

Monitoring an electric motor integrated in AN Automated SYSTEM

Alexandru Daniel TUFAN^1,*, Rémi BOUTON2, Alexandru Iulian TOMA3, Mihai SINDILE4

¹⁾ PhD Student, Engineering and Management of Technological Systems, University Politehnica of Bucharest, Romania.

²⁾ Student, Département Nord-Pas-de-Calais, Polytech'lille, Villeneuve d'Ascq, France.

³⁾ PhD Student, Engineering and Management of Technological Systems, University Politehnica of Bucharest, Romania..

⁴⁾ PhD Student, Engineering and Management of Technological Systems, University Politehnica of Bucharest, Romania.

Abstract: This paper presents the progress from the field of integrated automation and safety systems that assure a well functioning of manufacturing equipments. Nowadays, many devices have sensors that monitor operational parameters. This advancement was made in order to protect the equipment and to prevent them from malfunctioning or stopping. Considering that equipments work in real time, the system response is essential and must be instantly or with a response time as low as possible. Adopting an appropriate solution requires knowledge of automation as a complete development process, technological restrictions and also designing and choosing a solution so that the conceptual structure and enabling automation equipment meets the performance requirements of the system. Through this work it is intended to reach further to new solutions for the automation of a integrated system, the study of an active control of the parameters from a drive system of machine tools and programming of an automated system that has integrated logic. As an application, it is presented how a temperature sensor was implemented in a automated system in order to prevent the electric motor to overheat and malfunction.

Key words: Advanced monitoring, PLC, integrated manufacturing, TIA Portal, programmable logic.

pp. 29-38 View full text

FILLING PRESENT VACANCIES BY MEANS OF FUTURE ORIENTED RECRUITMENT PROCESSES

Valentina Mihaela GHINEA

Assoc. Prof., PhD, UNESCO for Business Administration Department, Bucharest University of Economic Studies, Romania

Abstract: Related to the organizational culture, we presently witness a change of paradigm: if formerly considered not more than a tool for internal integration and coordination, nowadays, it is recognized as being a vital ingredient of the company’s adaptability and effectiveness.In fact, there is a tendency towards another extreme: given the unwillingness of disregarding the organization tradition, values, agreed and shared objectives, some make a fixation for hiring strictly based on the organizational features. However, this way both the society and the organization’s evolution are neglected. Moreover, the abilities and competencies of the new hired risk not to be among the ones assuring on the long run a proactive existence to the company. In other words, compared to the interest aroused by the organizational culture, the study of its dynamics is almost inexistent, no matter if we refer to the universities research or the practitioners. The present paper aims proving that hiring only suitable people easy to integrate into the current organizational culture is effective rather on the short-run. Despite its numerous advantages, this human resource strategy neglects the ever increasing rigidity of a powerful organizational culture that is thus encouraged to absorb and homogenize any novelty. Thereby, in the attempt to reveal the dynamic character of the organizational culture, and the necessity of foreseeing the evolution of one’s own organization and of the world itself, we have accomplished a thorough theoretical research resulting in the G.VALI model. The latter suppresses the thesis of the static organizational culture and of everything that devolves from it.

Key words: recruitment, selection, organizational culture dynamics, HR strategy, G.VALI model.

pp. 39-44 View full text

CRACK DEVELOPMENT IN LINER USING CAGINALP PHASE FIELD MODEL

Marius TURNEA¹, Dragoş AROTĂRIŢEI^2,*, Mihai ILEA³, George CONSTANTIN⁴, Mariana ROTARIU⁵

¹⁾ Lecturer., PhD, Dept. Medical Bioengineering, University of Medicine and Pharmacy Grigore T. Popa”, Iasi, Romania

²⁾ Prof., PhD, Dept. Medical Bioengineering, Univ. of Medicine and Pharmacy Grigore T. Popa, Iasi, Romania

³⁾ Lecturer, PhD, Dept. Medical Bioengineering, Univ. of Medicine and Pharmacy Grigore T. Popa, Iasi, Romania

⁴⁾ Prof., PhD, Machine and Manufacturing Systems Department, University Politehnica of Bucharest, Romania

⁵⁾ Lecturer, PhD, Dept. Medical Bioengineering, Univ. of Medicine and Pharmacy Grigore T. Popa, Iasi, Romania

Abstract: The interface between stump and liner (socket) is subject of high pressure in different moments of gait cycle due to loading variation in body movement. The liner is the interface between socket and skin along with soft tissue and bones in a cycling loading. The result is a friction effect combined with pressure that conducts to the heating of skin and liner. The effect is and increasing of pressure and friction and the increasing the temperature again, in a cascading cycle than can conducts to fracture of liner and scars on stump.

There are models that describe the fracture development and prediction of crack propagation but in the last years, an increased attention is accorder to phase field models applied to fracture development as a better solution for analyze of fracture in different materials of composite materials. A simplified approach that use Caginalp model with memory is used to predict the fracture of liner under cycling loading. The numerical results of simulations are presented as results of theoretical approach.

Key words: Caginalp model, phase fields models, finite element method, crack development, fracture analysis, numerical methods, finite difference method.

pp. 45-50 View full text

TRANSITION FROM THE CLASSIC SERVICE OPERATIONS TO THE DECISION SUPPORT IN MAINTENANCE ACTIVITY

Ştefan VELICU¹, Ionel PAUNESCU², Daniel Marius PARASCHIV³

¹⁾ Prof., PhD, Machine and Manufacturing Systems Department, University Politehnica of Bucharest, Romania

²⁾PhD Student, Machine and Manufacturing Systems Department, University Politehnica of Bucharest, Romania

³⁾ Assistant Prof., PhD, Machine and Manufacturing Systems Department, University Politehnica of Bucharest, Romania

Abstract: This paper introduces the researches performed for highlighting the development from classic service operations to decision support in maintenance activity. The use of the monitoring software of Schindler Company – manufacturer of a different types of elevators – for viewing the operation of the studied technical system elements and the employing of the information collected for decision support in maintenance activity. The studied components are checked at the time indicated by the manufacturer and the monitored rates are measured when the new belt is assembled. If at the time limit the rates do not exceed the values required by the documentation, the system is allowed to run along a period a time increased by about 10% compared to the average time reported by the manufacturer. The research paper demonstrates that the use of a monitoring software helps to support the decision in maintenance activity and to achieve strong economic performances for the end-user.

Key words: service, solutions /monitoring/expertise software, capital repair, overhaul, maintenance.

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