Metoda de compactare dinamica cea mai utilizata o reprezinta aceea prin vibrarea unui mediu (pamant, piatra sparta, beton asfaltic ş.a.). Una dintre problemele constructive la placile compactoare vibratoare (PCV) este este legata de procedeul prin care se deplaseaza in timpul lucrului. Sistemele constructive pentru realizarea autodeplasarii PCV se pot grupa in functie de tipul vibrogeneratorului mecanic, de modul de amplasare al acestuia pe placa, precum si de modul in care se realizeaza virajul placii.
The most widely used dynamic compaction method is that by vibrating an environment (earth, crushed stone, asphalt concrete, etc.). One of the constructive problems with the vibratory compactor plates (VCP) is related to the process by which it moves during work. The constructive systems for the self-displacement of the VCP can be grouped according to the type of the mechanical vibrogenerator, the way of its placement on the board, as well as the way in which the turn of the board is made.

MECHANISMS USED IN THE SELF-MOVEMENT OF VIBRATORY PLATES

In aceasta lucrare s-a luat in considerare caracteristica efectului proiectarii mecanismului de antrenare a tractiunii locomotivei asupra principalelor forme de auto-oscilatii in timpul rotirii. In majoritatea cazurilor, s-a stabilit ca, este necesar sa se efectueze o simulare pentru cateva moduri de auto-oscilatie care sunt predominante, care simplifica analiza rezultatelor si selecteaza cea mai buna varianta a unitatii de tractiune.
In this paper, the characteristic of the dynamic effect of the locomotive traction drive mechanism on the main forms of self-oscillations during rotation was taken into account. In most cases, it has been established that it is necessary to perform a simulation for several modes of self-oscillation that are predominant, in order to simplify the analytical calculations and select the best results, respectively the best variant of the traction unit.

DYNAMIC CHARACTERISTICS OF ELECTRIC TRACTION LOCOMOTIVES

In lucrare se prezinta principalele conditii functionale si constructive impuse suspensiei unui vehicul feroviar si vibratiile maselor nesuspendate ale vehiculului, cu evidentierea influentei sistemului elastic asupra vibratiilor generate prin rularea pe cale. De asemenea se prezinta caracteristicile generale ale elementelor elastice din cauciuc si o serie de solutii constructive aplicate la rotile elastice ale vehiculelor de metrou.
The paper presents the main functional and constructive conditions imposed on the suspension of a railway vehicle and the vibrations of the unsuspended masses of the vehicle, highlighting the influence of the elastic system on the vibrations generated by running on the track. It also presents the general characteristics of the elastic elements of rubber and a series of constructive solutions applied to the elastic wheels of subway vehicles.

CONSIDERATIONS ON VIBRATION INSULATION EFFECTS ON THE ELASTIC WHEELS OF METRO VEHICLES

Automatizarea in sistemele de transport feroviar este in continua crestere. Inlocuirea treptata a controlului factorului uman necesita aceste sisteme pentru a garanta un nivel sporit de siguranta si fiabilitate. Insa, automatizarea sporita implica o complexitate sporita. O astfel de complexitate necesita analizarea diferitelor aspecte ale sistemului la nivelul adecvat de abstractizare. Metodele de modelare semi-formale si formale pot oferi un sprijin crucial pentru indeplinirea cerintelor de siguranta si fiabilitate si asigurarea mentinerii unui grad adecvat de abstractizare in timpul analizei. Mai mult, tehnologia de inginerie a liniei de produse ofera un instrument adecvat pentru a integra modelarea formala cu modularitatea sistemului. Sistemele de control al trenurilor bazate pe comunicatii (CBTC) sunt o noua frontiera a controlului si operarii automate a trenurilor. Platformele CBTC actuale sunt de fapt sisteme foarte complexe, care includ mai multe funcționalitati, iar fiecare sistem instalat, variaza in ceea ce priveste intinderea, sfera, numarul si chiar numele functionalitatilor implementate. Au aparut standardele internationale, dar ele raman la un nivel destul de abstract, stabilind in cea mai mare parte terminologia.
Automation in rail transport systems is constantly growing. The gradual replacement of human factor control requires these systems to ensure a higher level of safety and reliability. However, increased automation involves increased complexity. Such complexity requires analyzing different aspects of the system at the appropriate level of abstraction. Semi-formal and formal modeling methods can provide crucial support for meeting safety and reliability requirements and ensuring that an adequate degree of abstraction is maintained during analysis. Moreover, product line engineering technology provides a suitable tool to integrate formal modeling with system modularity. Communication-based train control systems (CBTC) are a new frontier of automatic train control and operation. Current CBTC platforms are in fact very complex systems, which include several functionalities, and each installed system varies in terms of scope, scope, number and even the name of the functionalities implemented. International standards have emerged, but they remain at a fairly abstract level, for the most part establishing the terminology.

PERFORMANCE AND OPERATING STANDARDS FOR CBTC SISTEMS

In lucrare sunt prezentate o serie de consideratii stiintifice care au stat la baza ultimei generatii de boghiuri cu osii orientabile, capabile sa "negocieze razele de curbura ale caii de rulare". Se urmareste astfel dezideratul "rularii pure". Prin orientarea radiala a osiei se elimina alunecarile transversale dintre roti si sine, iar daca rularea este conica se elimina alunecarile longitudinale, existand posibilitatea inlaturarii frecarilor si, deci, a uzurilor. Cum acest deziderat este ideal, apropierea de o "rulare pura" este posibila si astfel, pe langa o reducere a frecarilor ce imbunatatesc performantele dinamice ale vehiculului, creste si siguranta ghidarii in cale a vehiculului.
The paper presents a series of scientific considerations that formed the basis of the latest generation of bogies with adjustable axles, capable of "negotiating the radii of curvature of the roadway." This aims at the goal of "pure running". The radial orientation of the axle eliminates the transverse slips between the wheels and the rails, and if the rolling is conical, the longitudinal slips are eliminated, with the possibility of removing friction and, therefore, wear. As this desideratum is ideal, the approach to a "pure running" is possible and thus, in addition to a reduction of frictions that improve the dynamic performance of the vehicle, also increases the safety of driving the vehicle on the road.

CONSIDERATIONS ON THE DYNAMIC PERFORMANCE OF RAILWAY VEHICLES WITH ADJUSTABLE AXLES

Dispozitivele de comutare sunt tranzistoare bipolare cu poarta izolata de tip invertoare IGBT, fiind cel mai utilizate in electronica de mare putere specifica tractiunii feroviare, putand gestiona puteri de pana la 1,6 [MW] la o tensiune de intrare cuprinsa intre 3 si 25 [kV]. Elementul de stocare a legaturii de curent este condensatorul capacitor iar Invertorul standard este de tipul "cu doua niveluri", iar motorul de inductie este asimilat cu trei impedante simetrice. Cele trei tensiuni de iesire ale invertorului sunt identice cu frecventa fundamentala a sistemului de tensiune trifazat care urmeaza sa fie generata.
The switching devices are bipolar transistors with insulated gate type IGBT inverters, being the most used in high power electronics specific to railway traction, being able to manage powers of up to 1.6 [MW] at an input voltage between 3 and 25 [ kV]. The storage element of the current connection is the capacitor capacitor and the standard inverter is of the "two-level" type, and the induction motor is assimilated with three symmetrical impedances. The three output voltages of the inverter are identical to the fundamental frequency of the three-phase voltage system to be generated.

DETERMINATION OF DIRECT FIELD ORIENTATION VECTORS FOR THE ACTUAL OPERATING REGIME OF ELECTRIC LOCOMOTIVE MOTORS

Prezentul articol se inscrie in domeniul preocuparilor actuale privind cercetarea stiintifica si tehnica referitoare la constructiile practice realizate din materiale compozite, cu performante deosebite remarcate in practica industriala. In acest caz studiul se caracterizeaza prin analiza solicitarii maxime a unor compozite: a) cu fibre solicitate in lungul lor, b) dupa o directie oarecare c) una perpendiculara, d) stabilitatea structurii in lungul fibrelor, e) in directie perpendiculara sau f) o solicitare combinata.
This paper is in line with current concerns regarding scientific and technical research on practical constructions made of composite materials, with outstanding performance noted in industrial practice. In this case the study is characterized by the analysis of the maximum stresses of some composites: a) with fibers required along them, b) after a certain direction c) a perpendicular, d) stability of the structure along the fibers, in a perpendicular direction or a combined stress.

COMPARATIVE EXPRESSIONS REGARDING THE EVALUATION OF MAXIMUM STRESSES IN LONG FIBER REINFORCED COMPOSITES