Se face o prezentare a proprietatilor mecanice si fizice corespunzatoare panzelor laminate ranforsate cu fibra de aramid 7475-T761
There are showed 7475-T761 aramid fiber strengthened rolled sheets mechanical and physical properties

RESULTS CONCERNING THE ALUMINIUM ALLOYS ROLLED SHEETS MECHANICAL BEHAVIOUR (II)

Tendinta actuala de sporire a puterii locomotivelor electrice impune utilizarea cat mai eficienta a greutatii acestora in special in perioada demarajului, cand apare pericolul patinarii osiilor care se descarca.
The present tendency of increasing power electric locomotives require the most efficient use of their weight especially during the brooder, when appear the risk to slip axles that discharge.

THE VERTICAL AXLE LOADS VARIATIONS OF 480 SERIES LOCOMOTIVES TRANSMONTANA

In cazuri speciale de utilizare a motoarelor termice, pentru actionarea troliilor de sarcina ale macaralelor, studiul dinamic al regimurilor tranzitorii (pornire oprire) se face in conditiile impunerii unor marimi de intrare (legi sau pachete de legi) in scopul obtinerii unor performante dinamice superioare, avsnd ca efect cresterea productivitatii si diminuarea solicitarilor dinamice din constructia metalica a macaralei.
In special cases of use of heat engines for driving load winches of cranes, the dynamic study of transitory regime (on/off) is performed by imposing input data (laws or packages of laws) in order to achieve superior dynamic performance, resulting increased productivity and reduced dynamic strain in the metal construction of the crane.

STUDY OF THE DYNAMICS OF LOAD WINCHES DRIVEN HEAT ENGINE

Pentru determinarea caracteristicilor unui intreg sistem tehnologic, trebuie pre-determinate functiile de transfer ale tuturor sub-sistemelor care intra in alcatuirea acestuia, tinand cont de faptul ca modelul matematic al unui sistem se compune din corelarea tuturor ecuatiilor care caracterizeaza functionarea fiecarui sub-sistem din care acesta este alcatuit.
To determine the characteristics of the whole technological system, must be pre-determined the transfer function of all the sub-systems that it comprises by taking into account of the fact that the mathematical model of the system consists of the correlation of all the equations that characterize the operation of each sub-system of it is composed.

THE CALCULATION OF THE TRANSFER FUNCTION OF A SEMI-ACTIVE SEISMIC ENERGY DISSIPATION SYSTEM

Siguranta tehnica a structurilor mecanice este asigurata de calitatea activitatii de proiectare, de fabricare si de exploatare in conditiile impuse in faza de concepere. Materialele de constructie pot avea raspunsuri fidele sau discordante, in functie de natura lor intima, dar si din cauza unor diferenţe nedorite ale valorilor parametrilor de lucru, manifestate din conditii necontrolate. Materialele izotrope sunt mai bine cunoscute, in special cele metalice, in comparatie cu cele anizotrope sau ortotrope. Ca urmare, pentru precizarea vietii structurilor s-au elaborat mai multe modele fizice pentru rupere, dintre care in lucrarea de fata se mentioneaza unele dintre cele interactive, care s-au impus in practica industriala. Se reliefeaza diferentele dintre continutul exprimarilor matematice corespunzatoare, care au la baza atat studii teoretice, cat si experimentari pe materiale reprezentative. Se recomanda ca folosirea unui criteriu sau altul sa se adopte numai dupa cercetari experimentale minutioase, cu materiale testate in conditii de lucru, chiar excesive.
The technical safety of the mechanical structures is ensured by the quality of design, manufacturing, operating and exploitation conditions in the design phase. The building materials can have accurate or discordant answers, according to their intimate nature, but also because of some unwanted differences of the working parameter values, manifested in uncontrolled conditions. The isotropic materials are better known, especially the metallic ones, compared to the anisotropic or orthotropic. Therefore, to specify the life of the structures, more physical models were developed for breaking, of which, herein mentioned, some of the most interactive, which were imposed in the industrial practice. It highlights the differences between the contents of the corresponding mathematical expressions, which are based on both theoretical studies and experiments on representative materials. It is recommended that the use of a criterion or another to be adopted only after thorough experimental research, with materials tested under working conditions, even excessive ones.

A COMPARATIVE PRESENTATION OF SOME INTERACTIVE CRITERIA USED IN THE MECHANICS OF FRACTURING THE ANISOTROPIC MATERIALS

In vederea optimizarii eficientei procesului de cernere si a productivitatii ciurului vibrator inertial inclinat, au fot elaborate studii teoretice si practice privind comportarea materialului granular pe suprafata sitei vibratoare. Lucrarea prezinta o serie de aspecte teoretice, rezultatele teoretice prezentate fiind analizate si comparate cu cele obtinute pe cale experimentala, pe un ciur vibrator inclinat de 7,5 m2 din cadrul unei balastiere.
In a view of optimizing the efficiency of the screening process and the productivity of the inertial inclined vibrating screen, there were accomplished theoretical and experimental studies regarding the behaviour of the granular material on the sieve's vibrating surface. The paper presents some theoretical aspects, he theoretical results being analysed compared with the experimental results obtained in a gravel pit on a 7,5 m2 inclined vibrating screen.

CONSIDERATIONS REGARDING THE GRANULAR MATERIAL MOVEMENT ON THE VIBRATING INCLINED SCREEN’S SURFACE

Optimizarea parametrilor de proiectare ai structurilor din zona generica a constructiilor de masini constituie, la ora actuala, o chestiune de majora importanța; articolul de fata propune o abordare duala in ceea ce priveste optimizarea unei structuri avand drept criteriu de performanta rigiditatea acesteia. In urma tratarii prin calcul clasic, respectiv calcul cu ajutorul metodei elementului finit, se constata o buna dispersie a valorilor de referinta finale obtinute, fiind totusi necesara tratarea cu rigurozitate a modalitatilor de stabilire a ipotezelor de calcul initiale.
Structural optimisation remains a key issue in today’s constructive design and machine building area. The present paper covers a dual-approach example concerning traditional calculus method versus finite element analysis simulation for a given class of problems (statically determinate/indeterminate plane frame structures), in order to establish the level of confidence for a certain group of commercial finite element systems used as solvers in engineering problems. As a result of completing the above procedure, an excellent scatter plot of output measurements was obtained, however caution is advisable due to initial analysis parameter settings and strength of materials calculus hypothesis.

GLOBAL STIFFNESS RELATED STRUCTURAL OPTIMISATION

Lucrarea isi propune pezentarea unui model biomecanic cu patru grade de libertate al piciorului uman, in scopul utilizarii acestuia pentru studiul viitor al biomecanicii alergarii pe distanțe lungi (semimaraton si maraton). In acest sens, am dezvoltat un model pe baza unor masuratori antropometrice efectuate pe membrele inferioare ale unui sportiv amator. Modelul a fost apoi introdus in mediul de simulare 2D Working Model.
This paper proposes a biomechanical model with four degrees of freedom of the human leg, in order to use it for future study of the biomechanics of long distances runners (marathon and half marathon). Therefore, we developed a biomechanical model based on anthropometric measurements performed on the lower limbs of an amateur athlet. The model was then processed into Working Model 2D Dynamic Model Simulation.

A 4-DOF HUMAN LEG BIOMECHANICAL MODEL

O data cu cresterea importanta a vitezelor de circulatie la trenurile de calatori, se impun studii aprofundate privind posibilitatile de franare ale acestora, ca o componenta de baza pentru asigurarea sigurantei circulatiei. Scopul actiunii de franare este acela de reducere a vitezei de circulatie a trenului fie pana la o viteza inferioara, fie pentru oprire. In cazul vitezelor mari de circulatie, lucrul mecanic al fortelor de franare este foarte mare, fapt care are implicatii profunde asupra a cel puţin doi factori importanti: cantitatea de energie care trebuie disipata si, in legatură directa, lungimea drumului de franare. In scopul asigurarii unor drumuri de franare cat mai scurte, este necesar ca energia trenului sa fie disipata cat mai rapid, ceea ce impune utilizarea unor forte de franare cat mai mari. Acestea din urma sunt insa limitate atat de posibilitatea sistemului de a disipa caldura, cat si de deceleratiile imprimate care, in primul rand din conditii de confort ale calatorilor, sunt limitate la valori cuprinse intre 0,6-1 m/s2, cu eventuala acceptare, in cazul franarilor de urgenţa, a unor deceleratii instantanee maxime de 2,2 m/s2.
With the significant increase in driving speed passenger trains, the necessary braking depth studies of their possibilities as a basic component for ensuring traffic safety. The purpose of braking action is to reduce the velocity of the train either to a lower speed or stop. If a high-speed movement, the work of braking forces is very high, which has profound implications on at least two important factors: the amount of energy that must be dissipated and the direct link path lengths braking. In order to ensure roads as short braking, it is necessary to train energy dissipated as quickly, which requires the use of braking force bigger. The latter, however, are so limited ability of the system to dissipate heat and the decelerations printed, primarily in terms of passenger comfort, they are limited to between 0,6-1 m/s2, with eventual acceptance, if emergency braking, deceleration instant of maximum 2,2 m/s2.

CALCULATING THE QUICKLY BRACKING FORCE NECESSARY TO STOP THE HIGH SPEED TRAINS 401 SERIES - ERSTE ICE