Numar curent

Volumul 13 (2022), Nr. 2

CONSIDERATII PRIVIND FORMAREA PROFESIONALA SI AUTORIZAREA PENTRU CONDUCEREA LOCOMOTIVELOR
CONSIDERATIONS REGARDING PROFESSIONAL TRAINING AND LICENSE TO DRIVE LOCOMOTIVES
George DUMITRU, Radu Teodor COSTACHE, Mihai Victor POPA, Mircea DUMITRESCU, George PANAIT, Claudiu-Nicolae BADEA

Formarea profesionala si autorizarea in vederea conducerii locomotivelor se face in Uniunea Europeana si in Romania tinand cont de recomandarile cadrului de reglementare legislativ european aplicabil in prezent.
The professional training and the authorization to drive locomotives is done in the European Union and in Romania taking into account the recommendations of the currently applicable European legislative framework.

CONSIDERATIONS REGARDING PROFESSIONAL TRAINING AND LICENSE TO DRIVE LOCOMOTIVES

EVALUAREA SIGURANTEI SISTEMELOR DE SUPRAVEGHERE SI CONTROL A TRENURILOR BAZATE PE COMUNICATII (CBTC)
SAFETY ASSESSMENT OF SURVEILLANCE AND CONTROL SYSTEMS OF TRAINS BY COMMUNICATIONS (CBTC)
Alexandru BADEA, Gabriel POPA, Adrian Ioan MUNTEAN, Victor Mihai POPA, Constantin BIBIRE, George DUMITRU

Sistemele de control al trenurilor bazate pe comunicatii (CBTC) nu mai sunt izolate de lumea exterioara si deoarece folosesc alte retele pentru cresterea eficientei si imbunatatirea randamentului, ele sunt expuse la amenintari cibernetice foarte mari. In aceasta lucrare se propune un model generalizat de retea Petri stohastica (GSPN) pentru a capta interactiunea dinamica dintre agresor si aparator pentru a evalua securitatea sistemelor CBTC. In functie de caracteristicile sistemului si de metodele de atac - aparare, modelul a fost impartit in doua faze: penetrare si perturbare. In fiecare faza, s-au furnizat mijloace eficiente de atac si masurile defensive corespunzatoare, iar starea sistemului a fost determinata in mod corespunzator. In plus, au fost propuse o platforma de simulare semifizica si un model de joc pentru a ajuta la parametrizarea modelului GSPN. Cu probabilitatea la starea de echilibru a rezultatelor sistemului din model, propunem mai multi indicatori pentru evaluarea securitatii sistemului. In cele din urma, s-a comparat securitatea sistemului cu masuri defensive unice si cu masuri defensive multiple. Evaluarile au indicat importanta masurilor defensive si gravitatea situatiei de securitate a sistemului.
Communication-based train control systems (CBTC) are no longer isolated from the outside world and because they use other networks to increase efficiency and improve efficiency, they are exposed to very high cyber threats. This paper proposes a generalized model of stochastic Petri net (GSPN) to capture the dynamic interaction between the aggressor and the defender to assess the security of CBTC systems. Depending on the characteristics of the system and the methods of attack - defense, the model was divided into two phases: penetration and disruption. In each phase, effective means of attack and appropriate defensive measures were provided, and the state of the system was determined accordingly. In addition, a semi-physical simulation platform and a game model were proposed to help parameterize the GSPN model. With the equilibrium probability of the system results in the model, we propose several indicators for evaluating the system security. Finally, the security of the system was compared with single defensive measures and multiple defensive measures. The assessments indicated the importance of defensive measures and the seriousness of the security situation of the system.

SAFETY ASSESSMENT OF SURVEILLANCE AND CONTROL SYSTEMS OF TRAINS BY COMMUNICATIONS (CBTC)

STANDARDE DE PERFORMANTA LA OPERAREA CU SISTEME CBTC PENTRU GESTIONAREA SIGURA A TRAFICULUI FEROVIAR CU UN CANAL RADIO DIGITAL
PERFORMANCE STANDARDS FOR OPERATION WITH CBTC SYSTEMS FOR SAFE RAIL TRAFFIC MANAGEMENT WITH A DIGITAL RADIO CHANNEL
Alexandru BADEA, Monica VALU, Ion MATEI, Felicia Elena BIBIRE, Claudiu-Nicolae BADEA, George DUMITRU

Sistemul de control al vehiculelor maglev (SCMV) este de o importanta cheie pentru dezvoltarea transportului maglev. Lucrarea trateaza problemele gestionarii deplasarii in siguranta a transportului de tip maglev folosind un canal radio digital, analizeaza experienta internationala si trage concluzii in legatură cu practica. SCMV sa ia in considerare capacitatile fizice ale levitatiei magnetice, factorii si limitarile care afecteaza aceste capacitati, inclusiv factorii legati de siguranta. SCMV trebuie sa aiba un set de functii care sa permita implementarea eficienta, completa si sigura a posibilitatilor de levitatie magnetica in conditiile factorilor si limitarilor de mai sus. Scopul principal al SCMV este crearea si asigurarea constanta a conditiilor in care sa se realizeze functionarea si dezvoltarea sigura si eficienta a acestui nou tip de transport.
The maglev vehicle control system (SCVM) have a primary importance for the development of maglev transport. The paper addresses the issues of managing the safe movement of maglev transport using a digital radio channel, analyzes the international experience and draws conclusions about the practice. The SCVM shall take into account the physical capabilities of magnetic levitation, the factors and limitations affecting those capabilities, including safety-related factors. The SCVM must have a set of functions that allow the efficient, complete and safe implementation of the magnetic levitation possibilities in the conditions of the factors and limitations mentioned above. The main purpose of SCVM is the creation and constant assurance of the conditions in which to operate and the safe and efficient development and development of this new type of transport.

PERFORMANCE STANDARDS FOR OPERATION WITH CBTC SYSTEMS FOR SAFE RAIL TRAFFIC MANAGEMENT WITH A DIGITAL RADIO CHANNEL

EFICIENTIZAREA PROCESULUI DE OMOGENIZARE LA MALAXOARELE CU AX VERTICAL, PRIN MODIFICAREA SISTEMULUI ELASTIC BRAT- PALETA
THE HOMOGENIZATION PROCESS IMPROVEMENT AT VERTICAL AXIS MIXERS, BY MODIFYING THE ELASTIC ARM-BLADE SYSTEM
Virgil ENESCU, Polidor BRATU, Cristian PAVEL

Procesul de omogenizare a amestecului preparat la malaxoarele cu ax vertical este influentat de miscarea de auto-vibratie a paletelor ca urmare a incovoierii alternative a bratului de malaxor, modelat ca o bara elastica incastrata. In vederea modelarii matematice a procesului de amestecare, se considera cazul unui malaxor cu ax vertical cu capacitate de 3,0 mc, pentru care s-au determinat fortele de incovoiere, pulsatiile proprii ale paletelor, constantele elastice cat si amplitudinile miscarii vibratorii. In scopul cresterii randamentului procesului de omogenizare, se modifica succesiv, forma constructiva si implicit modulul de rezistenta si elasticitatea sistemului brat-paleta, urmarindu-se obtinerea de pulsatii proprii cat mai apropiate de pulsatia de excitatie a sistemului si implicit de amplitudini ale miscarii cat mai mari. Lucrarea isi propune deci o analiza a variatiei parametrilor miscarii de auto-vibratie a sistemului brat-paleta, cu variatia elasticitatii acestuia, in scopul eficientizarii procesului de omogenizare la malaxoarele cu ax vertical.
The homogenization process of the prepared mixture is influenced by the blades self-vibration movement as a result of the alternating bending of the mixer arm, modeled as an embedded elastic bar. In order to mathematically model of the mixing process, the case of a vertical axis mixer with capacity of 3.0 mc are considered, for which the bending forces, the blades own pulsations, the elastic constants as well as the vibratory movement amplitudes were determined. In order to make the homogenization process more efficient, the constructive shape and implicitly the resistance module and the elasticity of the arm-blade system are successively modified, aiming to obtain proper pulsations as close as possible to the excitation pulsation of the system and implicitly with amplitudes of movement as high as possible. The paper therefore proposes an analysis of the parameters variation of the the arm-blade system self-vibration movement, with variation of its elasticity, in order to improve the homogenization process for mixers with vertical axis.

THE HOMOGENIZATION PROCESS IMPROVEMENT AT VERTICAL AXIS MIXERS, BY MODIFYING THE ELASTIC ARM-BLADE SYSTEM

Dinamica interactiunii rulou vibrator - pamant in procesul de compactare
Dinamics of the vibratory roller – soil interaction in the compacion process
Dragos CAPATINA

Structurile rutiere sustenabile reprezinta un aspect esential pentru dezvoltarea economica si sociala a oricarei tari. In perioada actuala, exista preocupare sustinuta si, nu in ultimul rand, fonduri alocate pentru dezvoltarea unei infrastructuri rutiere la nivelul cerintelor UE. In aceasta lucrare sunt evidentiate fundamente teoretice, rezultate experimentale si concluziile necesare, obtinute prin studiul asupra dinamicii interactiunii rulou vibrator – pamant in timpul procesului de compactare prin vibrare.
Sustainable road structures represent an essential aspect for the economic and social development of any country. In the current period, there is sustained concern and, last but not least, funds allocated for the development of road infrastructure at the level of EU requirements. In this work, theoretical aspects, experimental results and the necessary conclusions are highlighted, all obtained by studying the dynamics of interaction between vibratory roller and soil while the vibration compaction process.

Dinamics of the vibratory roller – soil interaction in the compacion process

INFLUENTA RIGIDITATII SISTEMULUI BRAT- PALETA LA MALAXOARELE CU AX VERTICAL, ASUPRA RANDAMENTULUI PROCESULUI DE AMESTECARE
THE INFLUENCE OF THE ARM-BLADE SYSTEM RIGIDITY AT VERTICAL AXIS MIXERS, ON THE THE KNEADING PROCESS PERFORMANCE
Virgil ENESCU, Cristian PAVEL, Polidor BRATU

Gradul de omogenizare al betonului preparat reprezinta cerinta principala de performanta a malaxoarelor cu ax vertical. Procesul de omogenizare a amestecului preparat este influentat de miscarea de auto-vibratie a paletelor ca urmare a incovoierii alternative a bratului de malaxor, modelat ca o bara elastica incastrata in rotor. In vederea modelarii matematice a procesului de amestecare, se considera cazurile unor malaxoare cu ax vertical cu capacitati de 0,5 si 2,0 mc, pentru care s-au determinat fortele de incovoiere, pulsatiile proprii ale paletelor, constantele elastic, precum si amplitudinile miscarii oscilatorii. Compararea rezultatelor obtinute la cele doua malaxoare are ca scop scoaterea in evidenta a influentei rigiditatii sistemului brat-paleta, asupra parametrilor miscarii de auto-vibratie, implicit asupra randamentului de omogenizare a amestecului preparat. Lucrarea isi propune deci o analiza a parametrilor miscarii de auto-vibratie a sistemului brat-paleta pentru malaxoare cu ax vertical de diferite capacitati, in scopul eficientizarii procesului de amestecare, luand in considerare si eficienta energetica a fiecarui malaxor studiat.
The homogenization degree of the prepared concrete is the main performance requirement of vertical axis mixers. The homogenization process of the prepared mixture is influenced by the blades self-vibration movement as a result of the alternating bending of the mixer arm, modeled as an embedded elastic bar. In order to mathematically model of the mixing process, the cases of vertical axis mixers with capacities of 0.5 and 2.0 mc are considered, for which the bending forces, the blades own pulsations, the elastic constants as well as the oscillatory movement amplitudes were determined. The comparison of the results obtained with the two mixers aims to highlight the influence of the arm-blade system stiffness, on the parameters of the blades vibration movement, implicitly on the homogenization efficiency of the prepared mixture. The paper therefore proposes an analysis of the self-vibration movement parameters of the arm-blade system for vertical axis mixers of different capacities, in order to make the kneading process more efficient, taking into account the energy efficiency of each studied mixer.

THE INFLUENCE OF THE ARM-BLADE SYSTEM RIGIDITY AT VERTICAL AXIS MIXERS, ON THE THE KNEADING PROCESS PERFORMANCE

MODURI PRACTICE PENTRU EVALUAREA REZISTENTEI MECANICE ADMISIBILE A COMPOZITELOR ARMATE CU FIBRE TOCATE SAU CU PARTICULE
PRACTICAL WAYS TO EVALUATE THE ADMISSIBLE MECHANICAL STRENGTH OF COMPOSITESREINFORCED WITH CHOPPED FIBERS OR PARTICLES
Radu I. Iatan, Andreea - Silvia Nitu, Nicoleta Sporea, Luminita Georgiana Enachescu, Melania Corleciuc (Mituca)

Inca de la aparitia primara a compozitelor, acestea s-au impus in practica industriala, oferind caracteristici mecanice, termice si de rezistenta chimica sau eroziva, remarcabile. In acest caz studiul din acest articol se caracterizeaza prin analiza: a) rezistentei la intindere a compozitelor cu armatura dispersata (fibre tocate); b) rezistentei mecanice a compozitelor cu particule, c) rezistentei mecanice a compozitelor cu fibre whiskers / mustati / filamente. Sunt evidente combinatiile necesare pentru realizarea unor compozite cu performante mecanice, cunoscand realitatea influentei legaturilor intre componente, in procesele de fabricare.
Since the primary appearance of composites, they have prevailed in the industrial practice, offering remarkable mechanical, thermal and chemical or erosive resistance characteristics. In this case, the study in this article is characterized by the analysis of: a) the tensile resistance of composites with dispersed reinforcement (chopped fibers); b) mechanical resistance of composites with particles, c) mechanical resistance of composites with whickers fibers / whiskers / filaments. The combinations necessary for the realization of composites with mechanical performances are obvious, knowing the reality of the influence of the connections between components, in the manufacturing processes.

PRACTICAL WAYS TO EVALUATE THE ADMISSIBLE MECHANICAL STRENGTH OF COMPOSITESREINFORCED WITH CHOPPED FIBERS OR PARTICLES

Consideratii asupra sistemului de livrare a produselor in cazul automatelor de vanzare independente energetic
CONSIDERATIONS ON THE PRODUCT DELIVERY SYSTEM IN THE CASE OF ENERGY-INDEPENDENT VENDING MACHINES
Mihail SAVANIU, Oana TONCIU, Andrei TEODORESCU

Automatele de vanzare a produselor sunt tot mai prezente in comertul cu amanuntul. In contextul global al reducerii consumului de energie si al utilizarii energiilor alternative, am realizat un model experimental al unui automat de vanzare independent energetic. Automatele de vanzare sunt constituite din mai multe subsisteme iar cel de livrare a produselor are un rol important in bilantul energetic. Sistemul de livrare a produselor este un consumator important de energie, astfel ca in vederea optimizarii consumului acestuia, am realizat un simulator utilizand un soft adecvat. Prezenta lucrare prezinta simulatorul utilizat pentru studiul sistemului de descarcare a produselor in cazul automatelor de vanzare independente energetic.
Vending machines are increasingly present in the retail trade. In the global context of reducing energy consumption and the use of alternative energies, we created an experimental model of an energy-independent vending machine. Vending machines are made up of several subsystems and the product delivery system has an important role in the energy balance. The product delivery system is an important energy consumer, so in order to optimize its consumption, we created a simulator using an appropriate software. This paper presents the simulator used to study the product delivery system in the case of energy-independent vending machines.

CONSIDERATIONS ON THE PRODUCT DELIVERY SYSTEM IN THE CASE OF ENERGY-INDEPENDENT VENDING MACHINES

 
© 2011 Sinteze de mecanica teoretica si aplicata. Toate drepturile rezervate.